I have both external speakers (plugged into the 1/8" jack on the back of the PC) and headphones (in 1/8" jack on the front of the PC). My computer automatically mutes the speakers when I plug in the headphones and unmutes it when I remove the headphones. I'd like a way to leave the headphones plugged in, and control through which jack sound is sent via a keyboard shortcut (or taskbar icon if need be). I.e. I could hit CTRL-SHIFT-M (or whatever) to swap between speakers and headphones.
I'm using Win XP on Dell Optiplex hardware.
How can I do this?