hook up to pioneer vsx 50

I'm hoping someone can help me here as I'm trying to figure out something but can't find answers

i have a pioneer vsx 50 , with the output going to a projector (hd20)

i have a pc hooked up to one of my inputs via HDMI ( so it plays video and audio through my speakers out of my receiver and video to the projector)
I'm trying to run a karaoke/dj program out of the pc ( virtual dj) which plays fine audio and video ..

my problem is adding a microphone to the equation

i have contacted the virtual dj forums but they keep saying to hook up an external set of speakers which i don't want to do
my question is , is there a way to have the video from the pc input play on the screen and then simultaneously play audio from another source through the recieveer i.e. zone 2 ?

I'm thinking in theory i can have the pc input show the screen and then play sound via rca cable to the zone 2 ...will that work ?

hopefully i made sense and didn't confuse anyone as much as i am lol

so you mean run my karaoke program i.e. virtual dj for the video/songs

and then use the internal control for the mic and the sound will work for both ?