First, I would like to know if I can provide data validation on a cell that
has a formula in it (i.e. a cell that will not have a user enter a value). If
not, then I'm sol. If not, here's my scenario:

I have a cell that I do not want to calculate to over 450. There is a
formula in this cell that calculate 5 other summary cells. What I want to do
is setup validation so that if the calculation of this cell goes over 450 a
Stop error comes up. I know I can do this by setting validation rules for all
of the cells I will enter data into, but that's over 100 cells that already
have their own validation. I just want to know if there is a way to set this
validation rule on a cell that will have a formula in it and is locked so
users cannot enter data.

Thanks.