Weird license question.

[Cap'n Steve]

I already asked this at vbulletin.com, but they told me to ask here. What I'd like to do is develop a hack for integrating Perl programs with vbulletin. It's be in the form of a Perl module that would let you do some vbulletin tasks such as logging a user in or replying to a thread. I need to know if I'm allowed to basically copy some source routines into a the Perl module then modify them to be Perl compatible and release it here. I'd be willing to start from scratch, but it would be nice to be able to keep it as similar to the vbulletin source as possible. I didn't see anything related to this in the license, so if anyone has a clue, I'd appreciate it.