So managed to get the Home Screen up. You need to press Home and it brings up the Samsung menu. Scroll across to your VirginMedia source and you can see the Home icon above. Pick this and you are there. Hope that makes sense for your setup.
Given that it is an option there could be a way to remap one of the buttons on the remote to this function.
You can do that. Press the play pause button and it brings up a small menu on screen for you to go back and forwards. Its is very fiddly to use and I do not find it much use as I use the voice command on the 360 remote