Setting Server Group so they can't remove it.

So got my server back up and running.

Now i can't seem to figure out how to set the server groups.

I want to set a server group up so that only server admin can add it.
I also want it to be able to add groups, but not it's own or remove it

I've been going through the advance permissions and have got it so that it can add the groups i want (bar it's own)

Suggestions?

Setting Server Group so they can't remove it.