Try this. It's from a VIP722. I recently did my first work ever on a Dish Network system and had trouble assembling all the right codes for the Hopper 3 and the Joeys. Oddly, it turned out that the codes that worked for the Hopper also worked for the Joey.
I think this is the SEARCH command that worked for me. Since you can't just open an MX850 file and see the Hex that you used, I'm not sure. Please drop me a note if this doesn't work and I'll do the work needed to get the code out of the remote.
Oh, yeah, about putting the Hopper 3 on codeset 1: I saw this advice in several places, too. I called Dish tech assistance and found a person who was very knowledgeable about the system. She insisted that there is no such thing. I managed to pester her about it long enough for her to kick the call upstairs where a tech explained that the codeset thing did apply with the VIP systems, but the Hoppers and Joeys don't have that capability or headache. That's the moment when I tried the Hopper commands on the Joey and found they worked.
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw