scratchin with samples (HS/FZ-1)

'sup.. how can I do scratchin while playin a sample ? See, my problem is that when my HS1 (same as FZ1) is in scratchmode then it makes only scratchsound when I press a key & jerk da pitch wheel @ the same time but when I only press that key - no sound BUT I wanna do scratchin right in tha middle of that playin sample just like I'd do that w/vinyls ! Can any1 help me out or is that impossible ? uh, did I mention that I have no manual ?

P