Back button focus?

After figuring how to set up back-button focus on a couple of digital cameras, I got curious about doing it on my N80. No soap, you can use the custom shooting options to LOCK focus (CSM 11), but you can’t initiate focus with the AE-L/AF-L button. Anyone have any input?

2/22 I figured it out myself, set CSM 11 to 4
focus mode to C. CSM 7 to 1(puts AE lock on shutter button)

Set C-S-M switch to “C”
(this should have been included with original post