Howdy
The dude on the other messages board was correct in his response. You need to send a bank select / program change.
You were further correct saying you needed to put this code in the MPC.
What is the keyboard? Is it GM? If it is and you don't need anything other than the GM sounds, you can just send a program change.
If you want to go beyond the "capital bank" (that is, the default bank one gets by simply sending a program change) you need to send a bank select.
Typically, when sequencing it is good to have a blank bar (or two or how ever many you want) for "setup". In that setup bar, you can place preset mix info (patch changes, volume, panning, etc.)
The bank select message will depend on the keyboard you're using. If the keyboard is GM, the bank select messages use controller 0 (MSB) and controller 32 (LSB). So, a program change with bank select message theoretically looks like this:
1.1.000 controller 0, value x
1.1.005 controller 32, value y
1.1.010 program change, value z
If you have a MIDI implementation chart, you can fill in the values of x, y and z to suit your needs.