There are pins on the rear 20 pin connector that can be used to select many functions. Likely reverse engineering what he has is what you need.
Pins 3, 4, 6, 8, 12, and 14 are digital inputs and/or outputs. Pin 9 is an analog input. Programming those pins correctly and adapting the microphone to trigger them would get you what you need. I don't have the programming software with me, but it probably wouldn't take too long to figure it out.