An adapter cable. Is very simple, you want a square peg to fit into a square hole, there is no additional electronics involved.
Your mic-integrated headset most likely has a 4-barrel (collars) miniature 3.5mm (diameter) plug. You want a cable then, that has such 4-collar jack on one end and the other end splits into two cable (1) standard 3 collar 3.5mm stereo plug, (2) standard monophonic (2 collars) 3.5mm plug for the mic.
Go to Amazon and search away.