Auditing assignation of users to queries user groups

Question: We are using a lot of queries and we would like to be able to audit globally the assignations of a user to queries user groups.
The standard SAP transaction SQ03 gives the list of users assigned to ONE user group and moreover, if you are allowed with this transaction, you can modify the assignations.
We are trying to develop an Abap/Query but we can-t find no database table with the information (we tried all AQ* tables).
Thank's in advance for any reply.

Answer:
You would be farther ahead to assign the queries to a role and eliminate the need to maintian user groups at all. further if you assign a user to one user group they actually can run ALL queries in any group.

Answer:
Thank you for your reply and the good idea in it.
I don't understand how a user assigned to ONE user group could launch all the queries ?