What you would need to do is create a custom group.
Say called special users
Set the permissions to what you want.
Then add that user to the group.
I have done the same thing for non admins or non mods that post large attachments or pictures.
Or you could create a special users group and have members automatically added based on post counts.
The wiki has some info for setting permissions. It may not have the detail you are looking for yet.
