vBulletin Code Edit for Social Groups

Hello,

vBulletin 4.2.0 PL3
I have changed the permissions in Social Groups to only allow 1 created group but there is no addon or code to restrict users to only having 1 social group at a time.
I need it so members can only join 1 group at a time or leave there current group to join another.
Any help appreciated

Can anyone help with this?

I will pay for this quick edit if i have to

yawn....................