The idea of a VGA to HDMI cable is completely worthless. The crazy thing is companies actually sell them, but it really is basically a scam. VGA is an analog signal and HDMI is digital. A cable isn't going to perform an analog to digital signal conversion, so it just isn't going to work. In fact I recently found this website that talks about that very cable and what you can actually use to do what you're suggesting. Check out the really helpful VGA to HDMI Cable
Hopefully that'll really help clear things up and save you from wasting money on a VGA to HDMI cable that won't do anything for you. It wouldn't even make a good paper weight.