Windows Media Player as UPNP Client

I am trying to setup my Windows vista Media Player as an UPNP client. I have
an Xbox 360 and three windows vista machines in my home. One of the machines
is a media center with playon and rhapsody. My Xbox can see and play upnp
media from all of the various upnp media sources in my home. Among these are
PlayON, Rhapsody and the music collecitons from all of the windows vista
machines via upnp. I would like to be able to play upnp media between the
windows machines. In particular I would like the ability to view playon and
rhapsody on my other windows machines from within windows media player. I
can see the upnp sources in network neighborhood however when i double-click
the icons it seems not to open the media. The only media i see inside of the
windows media is the other windows media music collections.

This may seem weird but its important for me to be able to view the media
this way because I am using a home integrated music player which will only
play music out of the windows media player music collection. So if I'm able
to get this to work this way then it would enable me to view and browse the
music via remote controls in the home as well.

Is there any way to play upnp music sources out of windows media player
other than other windows media player libraries?