Im not sure of the question entirely, but I think you would use a soft sampler or hardware sampler to assign the samples to keyranges, and then use your controller keyboard to trigger them to the audio out of your soundcard and into your mixer.

Im not sure about sending audio via midi though? I think that would be real slow? I know you can do it with Akai samplers via recycle, perhaps you can doit sx too, I only got it today.