Additionner automatiquement les valeurs d'une même cellule

Option Explicit

Const cel = "A1"

Dim v

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
If Not Intersect(Target, Range(cel)) Is Nothing Then
  v = 0
  Target.Value = v
  Target.Offset(1, 0).Select
End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
If Not Intersect(Target, Range(cel)) Is Nothing Then
  Target.Value = v + Target.Value
End If
Application.EnableEvents = True
End Sub


Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Not Intersect(Target, Range(cel)) Is Nothing Then
  v = Target.Value
End If
End Sub