So you want volume control or any other oddball keys that aren't supported by Arduino? Fret not, my friend, for this short guide will help you get your keys (and any keys) remapped quickly.
Let's say we're using ctrl+pg up/pg down for volume up and volume down. The reason we want to use something weird here is because AutoHotKey will remap all keys, including th keyboard keys. That means if you tell c and v to remap to volume up and volume down, c and v will also be unusable on your keybaord. Though it sounds harder, it's a pretty simple process.
Download Termite from my website here