Enrolment

Hi everyone,
     I need to create a custom enrollment plugin that uses my Universities payment/ verification system. Me and a colleague have already written a perl script for oscommerce that uses my Universities verification/payment system in  a shopping cart  set up.  Can anyone give me pointers on doing this in moodle?  Can I just create an html page that allows  user to type there credit card information and then post it to the Universities payment/verification box, then if I get an ok from them, add the user to the course?  Any help would be appreciated.
Thanks,
Tyler Perkins