edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libs/win32ole.rb;C1200585
File: win32ole.rb
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libs/win32ole.rb;C1200585  (server)    2/26/2010 7:52 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libs/win32ole.rb;ComConversions
@@ -121,13 +121,8 @@
     /[{]?[0-9A-F]{8}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{12}[}]?|[0-9A-F]{32}/ =~ str
   end
 
-  # The DLR COM binder only supports core types like System.String as arguments.
-  # Passing in a Ruby String will not work. So we convert the Ruby types to
-  # CLR COM interop types as expected by the DLR COM binder
   def ruby_to_com_interop_type(arg)
     case arg
-    when String
-      arg.to_clr_string
     when Array
       element_type = ruby_to_com_interop_type(arg[0]).class
       converted_elements = ruby_to_com_interop_types arg
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubySymbol.cs;C1496258
File: RubySymbol.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubySymbol.cs;C1496258  (server)    2/26/2010 7:33 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubySymbol.cs;ComConversions
@@ -100,6 +100,10 @@
             return _string.GetCharCount();
         }
 
+        public static explicit operator string(RubySymbol/*!*/ self) {
+            return self._string.ToString();
+        }
+
         #endregion
 
         #region IRubyObjectState Members
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/Calls/InteropBinder.cs;C1594871
File: InteropBinder.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/Calls/InteropBinder.cs;C1594871  (server)    2/26/2010 7:22 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/Calls/InteropBinder.cs;ComConversions
@@ -24,16 +24,18 @@
 using System.Diagnostics;
 using System.Dynamic;
 using System.Reflection;
-using IronRuby.Compiler;
 using Microsoft.Scripting.Runtime;
 using Microsoft.Scripting.Utils;
-using IronRuby.Runtime.Conversions;
 using Microsoft.Scripting.Generation;
+using Microsoft.Scripting.Math;
+using IronRuby.Builtins;
+using IronRuby.Compiler;
+using IronRuby.Runtime.Conversions;
 
 namespace IronRuby.Runtime.Calls {
     using Ast = Expression;
-    using AstUtils = Microsoft.Scripting.Ast.Utils;
     using AstExpressions = Microsoft.Scripting.Ast.ExpressionCollectionBuilder;
+    using AstUtils = Microsoft.Scripting.Ast.Utils;
 
     internal interface IInteropBinder {
         RubyContext Context { get; }
@@ -128,7 +130,7 @@
                 DynamicMetaObject errorSuggestion) {
 #if !SILVERLIGHT
                 DynamicMetaObject result;
-                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindInvoke(this, target, args, out result)) {
+                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindInvoke(this, target, GetComArguments(args), out result)) {
                     return result;
                 }
 #endif
@@ -193,7 +195,7 @@
 
 #if !SILVERLIGHT
                 DynamicMetaObject result;
-                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindInvokeMember(this, target, args, out result)) {
+                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindInvokeMember(this, target, GetComArguments(args), out result)) {
                     return result;
                 }
 #endif
@@ -492,7 +494,7 @@
 
 #if !SILVERLIGHT
                 DynamicMetaObject result;
-                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindSetMember(this, target, value, out result)) {
+                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindSetMember(this, target, GetComArgument(value), out result)) {
                     return result;
                 }
 #endif
@@ -530,7 +532,7 @@
                 DynamicMetaObject errorSuggestion) {
 #if !SILVERLIGHT
                 DynamicMetaObject result;
-                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindGetIndex(this, target, indexes, out result)) {
+                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindGetIndex(this, target, GetComArguments(indexes), out result)) {
                     return result;
                 }
 #endif
@@ -584,7 +586,7 @@
 
 #if !SILVERLIGHT
                 DynamicMetaObject result;
-                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindSetIndex(this, target, indexes, value, out result)) {
+                if (Microsoft.Scripting.ComInterop.ComBinder.TryBindSetIndex(this, target, GetComArguments(indexes), GetComArgument(value), out result)) {
                     return result;
                 }
 #endif
@@ -805,5 +807,54 @@
             metaBuilder.Result = delegateFactory.OpCall(AstUtils.Constant(delegateType), Ast.Convert(target.Expression, type));
             return true;
         }
+
+        // TODO: copied from IronPython
+        internal static DynamicMetaObject/*!*/[]/*!*/ GetComArguments(DynamicMetaObject/*!*/[]/*!*/ args) {
+            DynamicMetaObject[] res = null;
+            for (int i = 0; i < args.Length; i++) {
+                DynamicMetaObject converted = GetComArgument(args[i]);
+                if (!ReferenceEquals(converted, args[i])) {
+                    if (res == null) {
+                        res = new DynamicMetaObject[args.Length];
+                        for (int j = 0; j < i; j++) {
+                            res[j] = args[j];
+                        }
+                    }
+
+                    res[i] = converted;
+                } else if (res != null) {
+                    res[i] = args[i];
+                }
+            }
+
+            return res ?? args;
+        }
+
+        // TODO: copied from IronPython
+        internal static DynamicMetaObject/*!*/ GetComArgument(DynamicMetaObject/*!*/ arg) {
+            if (arg.Value != null) {
+                Type type = arg.Value.GetType();
+                if (type == typeof(BigInteger)) {
+                    return new DynamicMetaObject(
+                        Ast.Convert(AstUtils.Convert(arg.Expression, typeof(BigInteger)), typeof(double)),
+                        BindingRestrictions.GetTypeRestriction(arg.Expression, type)
+                    );
+                } else if (type == typeof(MutableString)) {
+                    // TODO: encoding?
+                    return new DynamicMetaObject(
+                        Ast.Convert(AstUtils.Convert(arg.Expression, typeof(MutableString)), typeof(string)),
+                        BindingRestrictions.GetTypeRestriction(arg.Expression, type)
+                    );
+                } else if (type == typeof(RubySymbol)) {
+                    // TODO: encoding?
+                    return new DynamicMetaObject(
+                        Ast.Convert(AstUtils.Convert(arg.Expression, typeof(RubySymbol)), typeof(string)),
+                        BindingRestrictions.GetTypeRestriction(arg.Expression, type)
+                    );
+                }
+            }
+
+            return arg;
+        }
     }
 }
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Tests/Interop/com/apps/excel_spec.rb;C1044032
File: excel_spec.rb
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Tests/Interop/com/apps/excel_spec.rb;C1044032  (server)    2/26/2010 7:58 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Tests/Interop/com/apps/excel_spec.rb;ComConversions
@@ -55,6 +55,16 @@
         }.should_not raise_error 
       end
       
+      it "converts Ruby string to BSTR" do
+        @worksheet.cells[1, 1] = 'hello'
+        @worksheet.cells[1, 1].text.should == 'hello'
+      end
+      
+      it "converts Ruby symbols to BSTR" do
+        @worksheet.cells[1, 1] = :rubysym
+        @worksheet.cells[1, 1].text.should == 'rubysym'
+      end
+      
       it "can select ranges" do 
         range = @worksheet.Range('A1','B3') 
         range.Count.should == 6 
===================================================================