Problem with my Z4 sampler.

How do you assign more than one sample to a attached midi keyboard. I sampled three 4 bar loops from a 70's record , I timestrecthed them and now I'm ready to sequence them i want to assign the 4 bar loops to the midi controller so that i can just trigger them into my MPC. Is this even possible on a Z4?

Why use the midikeyboard at all? You can trigger the lop from your mpc, while it's loaded in your z4.
This is pretty basic stuff, and is well explained in both the z4 and the mpc's manual.