I gotta tell ya, I like that one too. Works like a champ. However, I
should've said. . . the "blank" cells, really aren't blank, but
contains LOOKUP formulas, and IF functions. If it doesn't find a value
in its lookup procedure, it returns a blank. The =SUM formula
referenced above works well, unless I include one of the cells in which
it didn't find a value, and subsequently displayed a blank cell.
(If the cell is 'truly' blank, the formula also works fine.)
Thoughts?

Thanks again for any assistance.
Pierre