Changer le signe d'un chiffe "+ ou -"

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Address = "$A$1" Or Target.Address = "$A$4" Then
        Application.EnableEvents = False
        Select Case Range("A1").Value
        Case "Dépense"
            Range("A4") = -Abs(Range("A4"))
        Case "Recette"
            Range("A4") = Abs(Range("A4"))
        Case Else
            Range("A4") = ""
        End Select
        Application.EnableEvents = True
    End If
End Sub