Events in SSRS

Hi, 

Is it possible to load a dataset when the report loads and then drive individual controls from it? 

I have a really complex report which uses about 12 stored procedures to fill various tablix controls.  I would like to load a 

dataset into memory and then point each tablix control to it using various aggregate functions.  As far as I can see (using BIDS 2008 / SQL 2008R2) each control has to be pointed at it's own procedure. 

Thanks in advance.