can car dealership program the garage opener from the handheld remote control

No. That is something for a garage door company not a car dealer, unless you are trying to use your car keyless entry on your garage door, never heard of that being done

You can read up on that if you so desire at: http://auto.howstuffworks.com/remote-entry1.htm

Also a discussion on that subject at: http://tl.acurazine.com/forums/showthread.php?t=570557 ..turns out is possible but very expensive

Also found: for Kia; http://www.fixya.com/tags/program_garage_door_opener_kia

If you are refering to the homelink mirror, I suggest trying homelink.com You should be able to program it yourself using their instructions.