I have a bar code reader that I can use to create a list of bar code
values, but there does not seem to be a way to be able to import them
into alexandria.

For example, the book with isbn 0-451-45282-8 will scan as
9976900499 45282

Date: 2010-10-30 20:52
Sender: gj keizer

Some books have two barcodes. I know some old books have barcode
inside book page and not outside. Check also inside book pages.
I have seen it by old Tokyopop manga books.
You can type number manually, but you can search first on internet,
so see if there is match in Google.

The ISDN code is valid, another is own code.