Is that wire connected to the headphones? If it is just a gold-plated 3.5mm female to male Y cable
, well, the net is full of people selling them, just google around for some selling to your country.
If you have some basic soldering skills you can expose the wires and solder them in something like this
(you unscrew the golden thing and it comes off exposing the places to solder your wires). You can find them in places that sell electronic components as well.