I want to make a cable for my Ultimate Ears 18 Pro. I want where the Y split, to have a male - > female 3.5 where the cable can disconnect like in the picture below:
 
 
 

 
 

 
So basically, the top part runs from the ear to 3.5 male plug where the Y split normally is (18 inches?) and then the rest of the cable continues from a female 3.5 to a male 3.5. So basically the rest of the cable is just an extension cable.
 
Any help or directions to people than can make this cable is greatly appreciated.
 
Thanks