Ban Usergroup from Specific Thread Prefix

[Liff]

Hey Guys,

I'm having an issue on my forum that would be solved if I could effectively 'ban' certain users from posting on threads with prefixes.

I've set up three discussion topics with a prefix and it's important for my users to be able to post on these threads without them being dragged off topic - There are only a handful of members who do this, mostly inadvertently.

I am able to use another modification to 'ban from thread' on an individual basis but it would be ideal to be able to do this by simply moving these users to a usergroup that cannot start or post on prefix threads.

Any ideas?

--------------- Added [DATE]1347174294[/DATE] at [TIME]1347174294[/TIME] ---------------

Alternatively, is it possible for a thread starter to be able to moderate their own threads and use thread ban themselves?