multiple mic inputs (win7 host to 2 xp vboxes)

[azLightning]

So I have an audio program that needs a mic input to work.. it doesnt support multiple instances in any way and i need to run 3 total copies of it. so i currently have 3 pc's powered up each with their own mic input from 3 diff sources.... decided vbox is a much more energy efficient way of doing this.. so my question:

Right now XP vbox #1 can successfully use the hosts onboard mic input... but i need to use the onboard mic to run audio program #1 of 3 using mic feed 1 of 3.. i just ordered a pci-e creative Audigy Rx 7.1 that has dual mic inputs.. I'll want mic in-1 to go to xp vbox #1.. mic in-2 to go to xp vbox #2.. Anyone see this as being a problem knowing the current status of Vbox? can i successfully configure the respective mic inputs to go to different vbox machines? I'm new so don't know much about the audio capabilities.. FYI - i tried using usb audio devices and there is too much delay/lag for my audio program to work properly.. its a decoding type application..

thx in advance