Mass Group Modification

[Hamma]

I dont know if this would be a hack or not - or if something like this even exists already.

I need to make a change to a bunch of usergroups based on last activity. I can use prune/move users for primary usergroup but I also need to revert additional usergroups.

Essentially here is what I want to do:

1. Find users based on Primary Usergroup
2. Further find users in that usergroup who have not logged in for 30 days.
3. Where both criteria match, move to registered.
4. Remove all additional usergroup permissions.

Pretty much what I am doing is reverting all users who have not logged in for 30 days to normal registered users as if they just came to the forums. Is there any easy way to do this? Thanks in advance if anyone can help me.