Mika, can you repeat that? Not understanding what you're saying.
The D600 is dual entry, so something like the Vmoda boom pro (which works with single 3.5mm inputs on the headphone) won't work. You'll have to go the old route of using a standard external mic like the Antlion mod mic. Any headphone can become a headset, but you'll have to contend with another wire going from your headphone to your source.