Change Volume keys to brightness keys?

Hi Folks,

I've got a Winbook and a couple of other low-end W8.1 tablets and I'd like to be able to adjust the screen brightness via the speaker volume keys on the side of the tablet. Anyone know how to reassign these keys? These are low-end tablets and just have plain vanilla W8.1 w/Bing and there are no "System Setup" like utilities as some of the larger name brands like HP and Toshiba have and there is nothing in Win8.1 w/Bing that allows you to reassign function keys that I can find. My guess is it will take a registry edit or an app to do it but I'd be grateful if someone who is more knowledgable than I am on Win8.1 could save me more searching!

Thanks!

Ok, possible solutions Autohotkey and KeyTweak. Weird thing though, KeyTweak shows the Volume - key and Volume + key as having the same scancode. Probably means that those buttons translate to a key combination and KeyTweak won't work so now to look to AutoHotKey!