OK.... Can we get this totally straight with what you are trying to do and what the precise equipment involved is... As I see it at the moment...
You have a, yet unknown type of, router downstairs. This has wireless and is where your internet connection comes into, but it's wireless range doesn't cover your villa..
To extend the range of the wireless you have 2 home plugs (This is a UK version....
http://images.eseller...alenet-pl-500av-2.jpg )....
You then want to plug the D-Link router into the upstairs home plug to extend your normal wireless range (presumably to watch porn in the bedroom wirelessly? :-P )
If this is the case...... it's possible, but not easy to explain!