Capture Cell Value Before Change Event

I am trying to capture the value of a cell before a change even. The attached Macro will report the value before the change but does not store it so that I can use it in another module. What I am trying to do is capture the value before the change and then look that value up in another worksheet (in the same workbook) so I can make the same change in the second workbook.

The values will always be in Column B and will always be string characters.

The code I am using for the change event is as follows:

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim OldValue As String
    If Flag Then Exit Sub
    If Intersect(Target, Range("B7:B132")) Is Nothing Then Exit Sub
    With Application
        On Error GoTo ErrHandler
        .EnableEvents = False
        .Undo
        OldValue = Target.Cells(1).Value
        .Undo
        .EnableEvents = True
    End With
    MsgBox "Value was " & OldValue
ErrHandler:
    Application.EnableEvents = True  
    If Err.Number <> 0 Then
        MsgBox "Error: " & Err.Number & vbNewLine & Err.Description
    End If
End Sub

Can you give me some direction on how to capture the OldValue so as to use it as a variable in another module?

Thanks...John