using .opt files

Following the readmes doesn't help, can anyone explain how to add opt files correctly into the XWA program so I can actually fly the ships?
I've tried creating an 2nd spacecraft.lst, adding the opt file to the others, adding a new line to spacecraft.lst and changing it to the ship's name but I don't get no new starfighters...
I'd appreciate any help, Cheers

[alecxwa]

i can't seem to get my opt files to work either, i put them in FLIGHTMODELS folder, but nothing happens, someone help me please!