Macro to write clicked cell value

I read this to mean keep what's in A1 and append what is clicked on in the B column.

So if A1 has 1 and you click on a cell in B that has 5 A1 now has 15. If that is not the case, then please explain further, a sample worksheet and an explanation would even better.

The code if you wish to use it on a different workbook has to go into the sheet module for the sheet you want it to work with. You do this by right clicking the sheet tab and choosing view code and pasting the code into the window that comes up. If you put it into a standard module it will not work.

The code is already installed on the sample sheet I attached. Enable macros and click on one of the numbers in column B and you will see the results.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If Not IsEmpty(Target.Value) And Target.Column = 2 Then
        Range("A1").Value = Range("A1").Value & Target.Value
    End If
End Sub

Change to:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If Not IsEmpty(Target.Value) And Target.Column = 2 Then
        Range("A1").Value = Target.Value
    End If
End Sub