Go to Radio Shack and buy a 10 or 20 ft "female stereo mini to a male stereo mini" cable. Then buy 1 "female stereo mini to male stereo submini" plug and 1 "female stereo submini to male stereo mini" plug. Then you'll have submini on both ends.
The stereo submini male is the same plug as the LANC. Should cost about $10-15 total. That's how I made mine.