[mythtv] Controlling the DCT2000 series STB

[Worldnet]

I am trying to create a setup where I can control multiple  STBs and  
navigate the Comcast OnDemand menus. I have the channel changing scripts  
working using the serial ports but I can't find any way to send anything  
other than the channel info to the STB. I need to send left, right, up,  
down and  select to the STB but since there are 4 STBs this info will have  
to be sent through the backend to get to the right box.

Mythtv breaks out the tuning info and sends it to the external tuner  
script but I don't see any way to send other info to the external tuner  
script. Is there a hook that I don't know about or is this  something that  
could be implemented?