In a roundabout way..
Windows current audio driver design doesn't allow for audio sources to send to more than once device at a time, but with a little trickery we can make it happen. I needed this to happen so I could have my music both at my main stereo and my remote speakers at the same time. THere is a slight delay.. probably a quarter of a second, due to this. but when the remote/wireless speakers are outside and the mains are inside, you can't notice.
First, in MM options, Output Plugins, Set the output location as Speakers. This will direct the audio to the headphone port. Now (In WIn7/Vista)right click your volume control icon, pick recording devices. right click in the new window, enabled "Show Disabled Devices".. A Stereo Mix will appear. Right click it, pick enable. Right click it again, pick properties, listen Tab, check the listen box, in the dropdown, pick your HDMI connection. HDMI might only be selectable when its connected. same will work for Optical/Coax.
I couldn't get my HT Receiver to output HDMI based audio to Zone 2 analog output. So I had to search up and figure out a way around the problem.