I solved this once with a php callback to a node forum that was hidden.
Each page was set to use a unique thread within it.
The callback got the posts from that thread for display.
A fake button to submit content linked to a thread/reply
Not sure if I can, first of all it has been a while and it was for 1.1 of XenForo. Also, it was made with a few people exclusively, I would have to track them down to get their permission to distribute it as a package.