I have read this old post, and I would like to provide another solution.
The problem with running Application.Undo is that Woksheet_Change runs again. We have the same problem when we restore.
To avoid that, I use a piece of code to avoid the second steps through Worksheet_Change.
Before we begin, we must create a Boolean static variable BlnAlreadyBeenHere, to tell Excel not to run Worksheet_Change again
Here you can see it:
Private Sub Worksheet_Change(ByVal Target As Range)
Static blnAlreadyBeenHere As Boolean
'This piece avoid to execute Worksheet_Change again
If blnAlreadyBeenHere Then
blnAlreadyBeenHere = False
Exit Sub
End If
'Now, we will store the old and new value
Dim vOldValue As Variant
Dim vNewValue As Variant
'To store new value
vNewValue = Target.Value
'Undo to retrieve old value
'To avoid new Worksheet_Change execution
blnAlreadyBeenHere = True
Application.Undo
'To store old value
vOldValue = Target.Value
'To rewrite new value
'To avoid new Worksheet_Change execution agein
blnAlreadyBeenHere = True
Target.Value = vNewValue
'Done! I've two vaules stored
Debug.Print vOldValue, vNewValue
End Sub
The advantage of this method is that it is not necessary to run Worksheet_SelectionChange.
If we want the routine to work from another module, we just have to take the declaration of the variable blnAlreadyBeenHere out of the routine, and declare it with Dim.
Same operation with vOldValue and vNewValue, in the header of a module
Dim blnAlreadyBeenHere As Boolean
Dim vOldValue As Variant
Dim vNewValue As Variant