It's not strictly possible to achieve this because entering new data into a
cell destroys the old data but you could use something like the following
which copies the existing data on selection of the required cell before you
type new data in.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Select Case Target.Column
Case 1
If ActiveCell.Value "" Then
ActiveCell.Offset(0, 1).Value = ActiveCell
End If
Case Else
End Select
End Sub

"walt007" wrote:

How does one automate the copying of old data in cell A to cell B when new
data is entered in cell A?