I'm not sure I understand exactly what JCH2122 is trying to do, but when I use the Dish receiver (installed in the RV) at home, I have an extra run from the home antenna that I tap into and run it to the outside "satellite" connection on the trailer. You normally have the ability to add another cable from the back of the antenna head just for that use.
Also, when on the road I use the portable Dish antenna for the trailer and run it to the "satellite" connection on outside of trailer. I have the receiver in the RV set up exactly like it would be in the house and run the living area TV and the bedroom TV on the Dish receiver (and can watch different shows on both). Also, set up both TVs with A/B switches so I can switch either of them to watch Dish or local channels (through built in antenna) or through the RV park connection on outside of the trailer.
Not sure I explained that so it is understandable or not.