how to manage group permissions?

Hey all, In my app users can create groups and the group creator can "kick" or "ban" users. I want the creator to be able to grant other members of the group to kick and ban. This is how I want to do it: I'm usgin acl_system2 and the creator can grant kick and ban permissions to group members by creating roles "kick_group_id" or "ban_group_id" for those users and then in the view I do:

<% restrict_to "(creator | kick_#{}) do %> <%= link_to "kick this user out of the group", group_membership(@group,membership),:method=>'delete'%> <% end %>

is this a good way to deal with this problem or is there a (way) better or simpler solution?

Thanx in advance