Sorry, you've lost me slightly there, and sorry I was a bit short earlier, I woke up with a hangover.
I did look at converters to do HDMI to component, but they start at £20 and I've no idea whether the quality is worth it as they have to have a circuit that converts the digital signal to analogue. The cheap cables don't do A to D. Similarly, the TV has VGA input, but as it doesn't have an HDMI input, there's almost certainly no circuitry in it to deal with a digital signal, so an HDMI to VGA cable won't work either.
I don't already have an Openbox, just a DM800HD. I did mention Eagleboxes in the other thread, but they were for folk in Spain, not easy for me to get one to try. Besides, though I could cope with the horrible menu system, the channel editing was hopeless & I spent too long moving channels around. The Openbox looked good as channel lists can be downloaded.
As good as the DM800 is too, visitors tend to struggle with it and give up. As this is for a spare room, I thought something very basic would be easier.