Yes, you need to make a new group. And edit permissions for the group.
Control Panel » Group Management
You will see a post count field to the right of users.
Whatever number you enter the member will be promoted to that group after the posts exceed that number.
Select the New group tab on the bottom left.
Add a new group.
Go back to:
Control Panel » Group Management
Set permissions for the group using the links on the right forums,site,cp

Then goto:
Control Panel » Registration Settings
Set the
Default Group(s) for New Members: to the newbie group you created.
I think that is it.
So a new registration will become a member of the newbie group.
With the permissions you set for newbies.
They will be promoted to users after the number of posts you set.



Blue Man Group
There is no such thing as stupid questions. Just stupid answers