Creating multiple personal address books

This is my first time using the Outlook forum. My knowledge of Outlook is pretty basic. I do have a bit of a time-consuming issue with Outlook.

Here is the basic scenario. Once a week I send ~30 emails to ~ 30 different districts around the country. The text within each email is exactly the same but the attachment for each is always different. Each email is sent to 4 or 5 individuals (recipient names are pretty much the same week-by-week).

The issue I run into is that it takes almost the entire day to send these out as I have to look up the names everytime in the global address book (which contains ~15,000 email accounts).

I tried to setup 30 different personal address books, but Outlook would only let me set up one. I basically want one address book for each district.

Is there an easier way to do this? Maybe put addresses in Excel or Word and create some kind of Macro to send? I am really stuck. I comments are greatly appreciated. Or if someone can refer me to a forum that deals mostly with Outlook questions. Thanks.

P.S. I am using Outlook 2003, Word 2000, and Excel 2000.