XF 1.5 Auto fill conversation fields (Like message area)

[DPF]

So I'm working in resource manager and using a generic bot to post resources kind of like a directory. But I want my members to be able to claim these resources as their own with a few simple clicks by sending a private message to the forum admins.

So I've created a link that automatically populates the Participants, and even the message title, but what I need help with is adding information automatically in to the message area if thats possible.

Thanks