Posting Topic From Outside of punBB

I'm working on a project where we wish to have an outside PHP script create a new topic in punBB, but allow users to post replies as normal within punBB (the new topics are actually going to be generated within Second Life, with some text content we want shipped to a punBB site).

It looks like I can scrape code from a WordPress to punBB plugin (http://punbb.org/forums/viewtopic.php?id=8373) but if there is something more direct, I'd appreciate it.