Key problem
 

I have a 1998 Explorer. Over the years, I've lost my keys a couple of times. Apparently, the system only allows a limited number of copies to be made, so my locksmith cannot make anymore copies and I'm down to my last one. I know the trick about taping it to the steering wheel, but I'd rather not that. Can a Ford dealer (or someone else) reset this so more copies can be made? Thanks.