You have two choices: Somehow figure out how to filter in C#.net or, bite the bullet and modify the stored procs. My opinion would favor modifying the stored procs. Script them out, use copy/paste to get the new join in there, where applicable. To me, the stored procs are responsible for passing the correct data to the presentation layer (.net). Simply my opinion.

Why would it not be feasible to modify the stored procs? Lack of experience in SQL? Lack of personnel? Or the shear number of procs? Just curious.

Edit - Watch which forum you post in (this is for SQL2005). Usually you'll receive quicker, more accurate answers by posting under the right platform....