EXS 24 Logic Sampler Users Group

I am looking to set up the EXS24 in Logic 8 to trigger samples via an
external MIDI drum pad controller. i.e a drummer hitting a drum pad live.

I want the looped drum sample to start when triggered via MIDI drum 
pad 1. But also to stop when triggered via a different pad, say pad2. 

I would also like to have it set up so the loop restarts itself when
the drummer hits pad 1 if the loop is playing i.e the band is going
out of time with the loop so the drummer hits pad 1 again and this
restarts the loop from the beginning. 

Any help is appreciated?
Thx in advance
Sam