I am trying to build a formula, where I can have assign a number to a phrase.
Specifically, I want to make a list of training classes people have attended,
and I want to enter a number in the cell, and have it grab the class name.

Conversely, I want to use the same cells, to auto fill another field, that
any numbers NOT in the first cell, will be auto-filled in the other field, to
indicate the name of classes NOT taken.

all help is much appreciated!