What you can do is use an IR router from xantech. www.xantech.com. Basically it is a switcher that has discrete codes for its outputs. What you do is put the IR command for the appropreate emitter before all commands for the Sat receiver you want to control.

You might have to put hoods on the emitters so you don't get any cross talk.

I'm pretty sure the codes for the Xantech RC68 remote are in the file section which is what you need to operate the device.

Hope this helps

Steve