I am not sure the purpose of the act that you intend to do. Even if you manage to add a parameter to any stored procedure, you need to use that parameter in some kind of logic being carried out by the Stored Procedure and since all SP will have different functionality, you will HAVE to do that manually !
But, considering you have some valid and well-thought reasoning behind doing what you intend to do, try to follow
http://stackoverflow.com/questions/4367184/sql-script-to-change-all-table-references-in-all-stored-procedures[
^]
This should serve the purpose. But do pay attention to warnings given by Solution providers there.
Hope that helps
Milind