Hi Ben,
Would the blank cell be in the value field or in one of the row fields?
If it is in the value field, would it work to use the value-filter on the parent row, and set it to "is not/unlike 0"?
Or if it is blanks in the row field, use the label-filter, and set it to "is not/unlike (blank)?
(not working on a english version of Excel at the moment, so the terms might be different)
Br.
Henrik