I've got a membership script built to work with clickbank.com. The script is written in PERL.
How it works is after a customer pays, they are brought to a signup page where it will display their clickbank receipt #. After they signup, their data is saved to a csv file, and they can login to the members folder which is protected using .httaccess and .httpsswd.
What I need done is when they login, I need that users clickbank receipt # to be retrieved from the csv file and displayed on the members page. That's basically it.