I think the "value" would suit your purposes
IN D1 TRY
"=IF(VALUE(A1)<=0,"",C1-B1)"

"egii" wrote:

I would like to use a logical test of If blank. It seems that I am able to
test for the value of zero, but not for blanks or an empty cell. I am
attempting to not select a cell if it has blanks or is empty, and do select
it if it has zero. In essence, I am selecting between plan and actual, and
the actual is to be selected when it has zero and when simultaneously the
plan has a quantity greater than zero.