How do I make comments invisible to certain users?

We use an excel sheet to publish work schedules to work place operators. We would like to put comments on cells, but not allow operators to see these comments. These comments deal w/ private personnel issues so rightfully should not be made public. Current securities force operators to open file in READ ONLY format (per user network profiles). Is it possible to do something that will make comments invisible to these users even if they hover their mouse over cell? The little red comment flag (corner of cell) can either be visible or not (perfer visible). Thanks, sauerj