Well, I guess I should start with some basic probing questions...
1. How does your perl script detect verses and link to the database (3rd party) site?
2. Do you have any experience at all in PHP? (I ask as any addon for a php script really should be in php)
As for licensed files; it's because if sharing said files we violate our license; as most of us here are gold license holders, that's like $800+ down the drain (Depending on when we renewed and the rates at the time).
I'd think that the site you're a member of would be somewat interested to have this done, is the owner not interested in providing you access?
Well, to link to a new page (like in the breadcrumbs bar above that links to the forum, portal, etc) a user would simply just add a link to the header.tpl file; so linking around isn't the issue, it's more how everything would work...
a good start would be to post your perl script and perhaps link us to a working version of the script; if someone is interested in taking it over I'm sure they'll comment.