Help with conditional formatting

Mark_Bean 

That cannot be done using conditional formatting. If you want to update the value in the cell itself, it requires VBA.

Let's say you want to apply this to C2:C100.

Right-click the sheet tab.

Select 'View Code' from the context menu.

Copy the following code into the worksheet module:

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim rng As Range
    If Not Intersect(Range("C2:C100"), Target) Is Nothing Then
        Application.ScreenUpdating = False
        Application.EnableEvents = False
        For Each rng In Intersect(Range("C2:C100"), Target)
            If rng.Value <> "" Then
                If IsNumeric(rng.Value) Then
                    If rng.Value >= 0 And rng.Value <= 45 Then
                        rng.Value = rng.Value + 360
                    End If
                End If
            End If
        Next rng
        Application.EnableEvents = True
        Application.ScreenUpdating = True
    End If
End Sub

Switch back to Excel.

Save the workbook as a macro-enabled workbook (*.xlsm).

Make sure that you allow macros when you open it.

Please note that Undo will not work for cells in the specified range.