If all of your sources are HDMI/DVI and you just need to get to the 990's on-screen menu, you could simply run a composite video cable to the TV. You don't need component just for the on-screen menu.

With cables in the wall, you could pull an HDMI/DVI cable and a composite video cable through using one of those existing HDMI's as a pull string and then use the HDMI/DVI and the 990's DVI switching to switch automatically between DVD and satellite with the composite there for onscreen menu tinkering. Just a thought...