Public Function Salim_Sum(Rg As Range)
    If Rg.Rows.Count > 1 Then
       Salim_Sum = "Error"
    Exit Function
 End If
Dim s#, itm As Range
  For Each itm In Rg
     If Not itm.EntireColumn.Hidden Then
       s = s + IIf(Val(itm) = 0, 0, Val(itm))
     End If
  Next
   Salim_Sum = IIf(s = 0, "", s)
 End Function