a stored procedure a list or a batch of SQL commands that you create on the Database that are executed as a group.
In CR, where you select the tables that you want on the report, instead of selecting the Tables, a couple of lines down is Stored Procedures, find the stored procedure that you created for your report and select it. That is pretty much all that you have to do as far as setting it as a datasource. Then just drag and drop as you would before.
HTH