Sub Test()
Dim DChiffre, D&, C As Range, Total As Double, xValeur As Double
With Sheets("Feuil1")
For Each C In .Range("A2:A" & .UsedRange.Rows.Count) 'Lecture de la colonne A)
DChiffre = Split(C.Value, Chr(10))
Total = 0
For D = 0 To UBound(DChiffre)
If IsNumeric(DChiffre(D)) Then Total = Total + DChiffre(D)
Next
If Total <> 0 Then C.Value = Total
Next
End With
End Sub