3 phase 208/120 Y panel
A to neutral 117.8, B to neutral 117.7. C to neutral 117.8 but
A to ground 140.0, B to ground 65.7, C to ground 172.2
I think I must have lost a neutral in one of my branch circuits and it is feeding back on my ground not sure. Difficulty is it is in a call ceter full of computers and the only way to narrow it down is to kill all the branch circuits in the panel and turn the circuits on one at a time until I find the circuit that is backfeeding. Am I on the right track? I s there an easier way to find it?
THOUGHTS?

Your diagnosis is probably correct. Circuit by circuit hopefully will show you the issue.
You already know what phase it is on.

The way to find this is with a phone. Call a qualified electrician!
This is absolutely not a diy job.