working with extra field in membership table

Hello All,
I m using ASP.net default Membership provider .My application has 3 levels SuperAdmin,Admin,User.
Where SuperAdmin will create multiple Admins and Admins will further create Users.  So Admins will create  users and then user will be able to login in the user a/c. Being a SuperAdmin i want to see which user has been created by which Admin .
So is there any way to insert the Admin UID  in "aspnet_Users "  table or any other way.
 
Thanks & Regards
 
 
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