Thanks for your replies everyone.

Seems one can always track n problem like this back to Database Design. I adjusted the design of the tables to include specific Grouping ID's that should have been present in the first place.

Using the grouping ID's i can now refer to n-amount of records by simply sending the procedure an appropriate Grouping ID instead of a comma delimited list of GUID's, and then using complex solution algorithms to breakdown the values.

Of course designing applications on Databases with weak designs tend to present a lot of problem.

Thanks Again.