the d50 has no CLS commander mode,. you can use the sb800 in SU4 mode with the built-in flash I guess but that's not giving you the coolness factor of CLS
Sil
edit,. I would also suggest an sb600 / sb800 - the iTTL metering and CLS is v cool and you can use it on camera or off camera with a nikon flash cord or use the sb800 as a master for other CLS flashes