how to automate user acconts?

Right now we have a custom web/php/perl app that runs on Apache and Red Hat. It lets teachers take their classes to the web page and create their own accounts. Once a teacher validates these (ie. no bogus accounts allowed), they are added by perl scripts into our NT domain as user accounts. I have two main problems:
1. this was all written and set up by our last admin and I have ZERO experience with any of the non-NT stuff.
2. the staff love it, but when we migrate to Active Directory, it will stop working.

What suggestions can you give me about possible commercial solutions, or even just re-writing the perl to work with Active Directory.

thanks!