Program mute vol+ vol- on a keyboard

I have a compaq internet programable keyboard (KB-9963) with 8 programable keys. I am running Windows 2000. I want to be able to push one key and have the music mute, push another key for volume + another for volume -. I have downloaded the compaq software and it does not have this option. Does anyone know what files or key strokes control the mute, volume.