Jack 3.5 mm audio to rj50

[Ceatza91]

Hey dudes,as the title says, is it possible to make this kind of cable? I have an nokia carkit, with an rj50 connector, and want to adapt it so i can use my smartphone instead of that verry old nokia phone in my car.

[Ceatza91]

this is the carkit http://pinouts.ru/CellularPhonesCables/nokia_ca-27_cable_pinout.shtml don't know on which pins to connect the Jack stereo cable. Any ideeas?