Confused on Ranking System

[White_Wolf]

What I want to do is take the assigned user group "V.I.P" and turn it into a post count as well. Perhaps I should re-explain that.

After I deem someone a V.I.P. I want them to have an increasing amount of stars in regards to their posts.

So I assign someone as V.I.P. and they only have 100 posts
when they hit 200 posts, they get an extra star, and that should be automated- post-count group; not assigned group.

But when I try to create the V.I.P. post-count group, it won't save the group (I assume because I already have that marked as an assigned-group). So I made a post-count group named "VIP" (no periods) and it accepted this as a post count group (and is designated 2 stars at 200 posts). But when I tried to create the second level of VIP -3 stars at 500 posts- it wouldn't accept it (I suppose because the name VIP already exists as a post-count group)

So I'm not sure how to do this.

Any advice?

Also, when people first sign up, I want them to belong to a default group with specified permissions. Right now they sign up and are marked as "unassigned". I want to make sure their permissions are set low when they first sign up so that they don't start trolling around when my back is turned.