How can I limit posting/attachment/linking from new users?

[Strat]

I checked the usergroup, posting options, etc. I just can't find where I could modify these options.

I'd like to add a value that states that new users can't post links or attachments before they hit 5 or 10 posts.

Where can I do this?

EDIT : I have 3.5

Aw, come on. Nobody knows how to do this? Yeah, right.