If what you are trying to do is to use a drum map, I used to do that, but the Step Sequencer has issues with going back and trying to edit using Step Sequencer when the original track was made using Step Sequencer with a drum map. (I used Battery 3 but that shouldn't matter)
I had to bounce the track to midi to get past that. Twas a nightmare for me until support finally told me I shouldn't use drum maps with Step Sequencer.
If on the other hand dubdisciple is referring to something within SD3 then please disregard my comments, except this one. :)
Bob Bone