Automating XMP Metadata in Illustrator CS4

How do I use actions or scripting within Illustrator CS4 on the Mac to automatically copy all of the text within an Illustrator pasteboard and paste it into the Keyword XMP Metadata field under File Info.

I've tried Select/Text objects, then Copy (Cmd-C), File Info (Shift-Cmd-Opt-I), Paste (Cmd-V after clicking in the Keyword field), OK.

It works fine manually, but the File Info sequences are not saved in the action.

Thanks for any help I can get.