Hi Rich,

First of all, record the vocal track as normal.

Then record a midi track of what you want the harmony to do.
You can use any instrument sound for this - it won't be heard eventually.
Label the midi track "GUIDE".

Now highlight the original audio track and go to GENERATE - GENERATE AUDIO HARMONY.
The Audio track should be the one you highlighted.
The harmony type should be SINGLE MONO AUDIO.
Select a blank track for the audio output - very important, or it may over-write an existing track.
In the top left dialogue box, choose "MIDI PITCH TRACKING" and select the GUIDE track.
Hit "OK"

That should get you there.

Cheers, ROG.