Main set up

alright i pretty much have things set up ok.
but i want to be able to hear the mpc through my amplified speakers and hear the computer sounds also.
i have a us 122 sound card for recording.
i have hosa 1/4 plugs for the stero out plugged into the speakers.
but i have to constantly switch back and forth between the hosa plugs that are plugged into my soundcard just to hear the computer sounds.
the soundcard has other outputs for guitars but that doesn't help me much. it's got to be a way that everything can be hooked up together.

Plug your MPC output into your sound card input, all you need to do then is fiddle with the sound card's mixer software to get it to pass the MPC sound through to the speakers...simple as that.