Im not sure if I follow you, but are you could sample all the sounds into your mpc and save them as .wav or .snd if you want.
But if you trying to use your mpc in conjunction with your sound module you need a mixer. You will go out of the mpc into the mixer, out of the module into the mixer. This will allow you to hear both the sounds of roland and mpc at the same time. Hope this answers ur question....
Blessings to all...