The HTC desire doesn't have a physical keyboard so there is no keyboard plug. What device have you got?

 

unless he means the four at the bottom and trackball?

 

Something like this?

HTC Desire UI Board

You could try to repair the flexi, but unless you have a very fine iron and a microscope it's not worth trying. Even then it's a dodgy procedure, get it too hot and the flexi will disintegrate.