Sorry to dissapoint you fella but the aux port is for sound only (and that can be hit and miss due to the poor build quality of the socket).
If you want ipod control with track display buy a new Ford with USB port or ditch the Ford headunit for a decent after-market one.
It is Possible though
you need the Focus Bluetooth unit with USB then the Mondeo cable assembly the mondeo bezel and USB socket and microphone you may or may not need an extra wiring harness for radio £20 ish
total cost is around the £190
If you are intrested My mate at Ford will supply the parts and i can describe how to YOU get the USB socket which allows control and display of Ipod or USB stick with MP3s on and as a bonus you also get Hands free Bluetooth and a voice control of compatable items
I will pass you to my mate trevor who will tell you what is needed and the cost
It is well worth it I use I pod classic 160 gb that is Full about 3 months worth of none stop mp3s lol