[yopeople70]

Because of the two 3.5mm jacks on the headphones, can I plug in a microphone, lets say the Vmoda Boompro microphone, into the jack I am not using to create a headset to use on my computer?

 

[PETEREK]

  Because of the two 3.5mm jacks on the headphones, can I plug in a microphone, lets say the Vmoda Boompro microphone, into the jack I am not using to create a headset to use on my computer?

You're wanting to connect 2 cables to your NAD? Why wouldn't you just use the BoomPro for both audio and the mic but connect it to a splitter?
 
Use this with the BoomPro:
http://www.amazon.com/StarTech-MUYHSFMM-Headset-Splitter-Adapter/dp/B0058DOWH6
 
Depending on how far apart your PC and your source are from each other, you may need a 3.5mm extension: 
http://www.amazon.com/C2G-Cables-13787-Female-Extension/dp/B00007FGU7