RFX6000 is a proprietary solution and likely is not easily be controlled via a computer. If you need discrete outputs, consider the Xantech RT-8 or the RT-16 which gives you the ability to send an IR code to setup the switch to a particular or all outputs (blaster) and then send the IR code you desire. I used to use this exact solution for controlling 3 Sony DVD Changers all set to Command Mode 1.

If you search on Amazon, I am very sure you will find one for sale in mint condition and I'm sure you can also find them on Ebay.

So, effectively, you could do what you want for each zone with a Single Global Cache ITaq IR and a Xantech IR router (RT-8).