My home came with a network of cabling to distribute cable tv signals. When I dropped cable in favor of dish network, I disconnected the cable feed and used the cabling backwards. That is, my satellite receiver feeds RF (channel 2) into the cable for use elsewhere.
Since my satellite receiver remote is IR/UHV I can control the satellite receiver anywhere. I bought an extra remote on ebay and use that in the bedroom.
I've examined the web page for smarthome that was suggested earlier in this thread and it looks to me like it will fill your needs. However I would still phone the smarthome people and ask about it. Ask them 'If I have a tv in a room with a closed door, will my normal tv and remote work?'
I just thought of something. If your direct tv receiver is like mine, it will output a single channel simultaneously in video/audio and composite video. You will have to use the remote that matches the direct tv receiver. The comes-with-the-tv remote doesn't work here. Do you have this situation?