Brian,

Could this UDF be of help?

Function CellHasFormula(c as Range)
If Left(c.FormulaR1C1,1) = "=" Then
CellHasFormula = True
Else
CellHasFormula = False
Endif
End Function

If your sheet layout allows it, you can populate helper columns with
=CellHasFormula(A1)
and then filter on True/False.

HTH
Kostis Vezerides