Guru's:

This is a tricky one!

Is it possible to have a calculation formula in a cell or set/range of cells
if one condition exists and allow for data entry if needed and still have the
calculation take place against the entered data under other conditions?

Say, cell F5 - Q5 are calculated formulas based on a value entered in cell
E5, but under other conditions, I'd like to either add or enter values into
cell, If there is no value in E5 (Show all cells blank), then allow for
manual data entry as needed and do calculations against cell F5 - Q5 those
entered values? In code, I guess, that would be an If ThenElse statement, is
it possible in excel?

Thanks in advance...