Although the recommended way is to simply have a BDM header (a mere six pins) on the target board, I seems it would be simple to make a programmer with a socket. I've just never seen one.
So if you know where to get the right size socket, let me know too. All the board needs is a power supply, clock, the BDM header, the socket, and misc 0.1 uF caps. Then you could call it the adapter you're looking for.