Donation Usergroup

[Irishnotsane]

Okay so I have a usergroup called Donors & it has different permissions than other usergroups, such as ability to edit/move own threads, open/close threads etc...

I also have the AW Coding Donation System installed so that when someone donates and I confirm it, it then ADDS "Donors" to their account as an additional usergroup. This MOD also have the function to MOVE a user to the donors usergroup as a primary usergroup.

No one on my forum can edit their own posts apart from Moderators/Admins and Donors.
Is what I'm trying to do is make it so that when a user donates to my forum, they get added to the Donors usergroup, granting them access to edit their own posts etc, however I wish for their forum permissions to stay the same.

I can't seem to get my head around how to do it, if even possible.

Example:

Lets say I have 3 usergroups and under them are the forums they have access too.

Usergroup 1
- Forum 1
- Forum 2

Usergroup 2
- Forum 3
- Forum 4

Donors

A Member registers and automatically go to Usergroup 1 so they can only see Forum 1 & Forum 2 and has no permission to edit/move ..(etc).. their posts.
that user then donates and gets added to Donors

That member can only see Forum 1 and Forum 2, and now has the ability to edit/delete, move, close their own posts/threads.

If that even half makes sense
Help would be GREAT!