VBA - cell referencing

Try

Private Sub Worksheet_Change(ByVal Target As Range)
Const WS_RANGE As String = "A1"     '<== change to suit

    On Error GoTo ws_exit
    Application.EnableEvents = False

    If Not Intersect(Target, Me.Range(WS_RANGE)) Is Nothing Then
        With Target
            Me.Range(.Value2).Value2 = Me.Range(.Value2).Value2 + 1
        End With
    End If

ws_exit:
    Application.EnableEvents = True
End Sub

This is worksheet event code, which means that it needs to be
placed in the appropriate worksheet code module, not a standard
code module. To do this, right-click on the sheet tab, select
the View Code option from the menu, and paste the code in.