Sorry, this is four years late !!!
(At that time, as a neuroscientist, I was rather busy with neuronal signals).
Today, with SAS 9.3 and DOSUBL function, you can run your PROC IML code within the DATA step containing active hash objects. From my experience with other PROCs and DOSUBL, the hash objects can interact with the PROCs and vice versa, within the same DATAstep.