The following event code should do what I said (mimic Conditional Formatting
for #DIV/0! errors only). Note that, as written, it looks for these errors
in Columns A and B only (this can be changed to another column or an
arbitrary range if needed by changing the address assigned to the Addr
constant in the code); and the code assumes there are formulas in Column B
(that is, the assumption is that your user didn't simply type =2/0 into a
cell in Column B, but rather, a formula in that column evaluated to the
error).
Private Sub Worksheet_Change(ByVal Target As Range)
Dim R As Range
Const Addr As String = "A:B"
On Error GoTo SkipIt
For Each R In Target.Dependents
If Not Intersect(Range(Addr), R) Is Nothing Then
R.Interior.ColorIndex = xlNone
If IsError(R.Value) Then
If R.Value = CVErr(2007) Then R.Interior.ColorIndex = 3
End If
End If
Next
SkipIt:
End Sub
You would install this event code by right-clicking the tab at the bottom of
the worksheet you want to have this functionality, selecting View Code from
the popup menu that appears and then copy/pasting the above code into the
code window that opened up.