Blocking BB code use by certain usergroups

[gef]

Hi,

I'm having a bit of trouble with spam at the moment, and am going to try and combat this by setting up a "newbie" usergroup that people automatically join when registered. After 10 posts, members of this group are promoted to the "members" group.

However I can't see any settings to prevent the newbie group from using BB code on the forum. Basically I want the standard members group to have all the usual functions, but the newbie group can't post in polls or use BB code in posts.

Poll voting in controlled in the usergroup settings, as is the use of BB code in signature. But I want to ban BB code in posts, for all forums, just for this usergroup.

Have I missed something obvious? Any ideas?

Thanks!

Gef