u mean note repeat right? you can change the note settings to 1/16 or 1/32 or whatever and that will give u a different roll. Or you can assign two snares to two pads right next to each other, record at a very slow tempo at first and hit both pads and try to make a roll that way. Then you can spead the sequence up and it will sound like a roll.
Don't use step edit to make rolls though, use the note repeat button, thats what I use.
I did drum rolls in this track:
http://www.djxeno.com/singles/ghosts.ram
Peace,
-XeNo-