Help finding a script or software

Can anyone tell me how to automate the following:

I want to give my customers a code. They go a web page and enter the code along with their contact info, then are given access to their bonuses.

I need to create a bunch of different codes so I can track which media the visitor came from (from an email, direct mail, etc) and store this code and contact info somewhere.

I was thinking of just creating a spreadsheet with all my codes. Then create a custom and required field in my autoresponder to store the code and contact info.

I was hoping their was script or software out there that would help keep this organized.

Thanks!

CopyCub