I dont think this will see the light of day...
The simpler thing to do is for Dish / Sling to write a Media Center plugin for Windows Media Center and you are good to go, with a 922 or any slingbox enabled receiver.
Hate to be a bad guy here, but from what I have been told is you can not record Dish Network programming on the Windows Media center platform.
IF that is the case then you could see why a Sling plugin would be a better idea.