DDJ-1000 : Stems on knobs

Hi guys, 

I actually play my tracks on channel 2&3.
I whould like to map Stems on high,middle,bass knobs (deck channel 1&4) to control Deck 2 & 3 .
I whould like to activate stems on the knobs of deck channel 1 for the deck2 & activate stems on knobs deck channel 4  for the channel 3. 
I actually use the PadFx1 to use Stems but its not so good to turn stems smoothly.

Can't achieve the mapping cause too many conflicts with other mapping assignations. If someone can help me it whould be greatfull !

Kind Regards.
Baze Selecta