Just go into Banner Settings and create a unique profile for each page you want to track referrals from. Then use that URL in only one place, and when you run your reports, you can run them by profile.
The URL will wind up looking something like this:
xhttp://banner.examplecasinohere.com/cgi-bin/banner.cgi?id=N&member=yourmemberid&profile=uniqueprofilehere
Might vary from program to program.