Have finally found a way to automate putting an individual into a secondary group automatically, based on the value entered in profile fieldX. The above request was just a work-around until I could pull this off.
For anyone interested in the auto-add code, see
https://vborg.vbsupport.ru/showpost....40&postcount=9
So now I no longer need that new field we added to the user table, above.
Is getting rid of it as simple as going into phpmyadmin, selecting this field and choosing "Drop"?