At least I think that's what I need to do.

Our contractors' commission on parts is 40% if they purchased the part
themselves, and 30% if the office provided the part. The way it's set up now
is the tech types "y" if they purchased the part, and "n" if it came from the
office. So then we calculate their commission.

So what I think I need is to have a hidden formula I can refer to in the
cell that contains the $ amount of the part (hidden formula would be .40 for
y, .30 for n).

Is this possible? Or can you recommend another way to handle this?

Thanks!