Cable to split N8 3.5mm socket to standard mic and headphone jacks

[ec42]

Hey,
so I have
* an N8
* a car with an aux 3.5mm input socket for the stereo, and
* a microphone from an old car kit with a 3.5mm mono jack.

I reckon that's got the making of a very cheap car kit, if I can find a cable to split the N8's 4 pin 3.5mm socket to stereo 3.5mm hardphone and mono 3.5mm microphone.

So I tried a couple of things from Amazon (http://www.amazon.co.uk/gp/product/B...ls_o01_s00_i00 and http://www.amazon.co.uk/gp/product/B...ls_o06_s00_i00) which don't work.

Is this possible? Can someone point me in the right direction. Many thanks,

E