It seems to me (and I'm not saying this would get done for free), that when you call to activate the HR 34 you tell the CSR that you want to re-locate one of your HR 20's to a different room without coax. They should set you up with a home service call. Before you call, unless you already have a SWM 16 you will have too many tuners (i.e., 2 HR2X's= 4 plus HR 34= 5 for a total of 9), you should tell them you're getting an error message of not enough tuners, and they should add a SWM 16 to the order.
In short, this should be do-able. Again, I am not saying it's going to be free, but overall what you're needing to do, has been done by others who have posted on this forum.