Set up shortcut keys for your games and apps.

Right click on the icon and choose properties.

Sometimes the screen you need is right there and sometimes you have to select to go to the "programs" tab. You can't select the shortcut key to be "G" or "R" but it can be "Ctrl + Alt + G" or "Ctrl + Alt + R". If you want to setup to use just a single button for a shortcut key you can use on of the function keys along the top.