So you have VGA to RJ45 at one end and at the other end is where you are stuck.
The main problem is that as its VGA going in it so it will be VGA coming out the other end. It is possible if the TV scart socket supports it. You can get VGA to scart leads, you will also need to make sure its a scart in Lead and not scart out..
Another option which will work is to get a PC VGA to TV converter. Amazon do one for about 11 pounds.