Interesting enough, I built a series of MAC 101 fixture models in XML to do pixel mapping. Moreover, I assigned the Pan and Tilt to Red and Green channels of a different mix and then used an algorithm to create a video file where the fractals were driving the X and Y movement.

It was a concept and never made it past C4D and ESP Vision but it did work quite nicely.

Marty's suggestion works and is most always correct. However, if you desire the remaining parameters in a DMX controller, you'll have to do the DMX separation and interception in an external device.

Even in my scenario, I had to build a DMX interceptor in MAX/MSP to sort the DMX from the two fixture types into one.