Option Explicit
Sub Essai()
If ActiveSheet.Name <> "Feuil1" Then Exit Sub
Dim n&: n = Cells(Rows.Count, 1).End(3).Row: If n = 1 Then Exit Sub
Dim T, s$, p$, a&, b&, c&, i&, j&, k&
n = n - 1: T = [A2].Resize(n): k = 2: Application.ScreenUpdating = 0
With Worksheets("Feuil2")
.Columns(1).ClearContents: .[A1] = "N° de Téléphone"
For i = 1 To n
s = T(i, 1)
If Len(s) = 21 Then
If Mid$(s, 11, 1) = "-" Then
p = Left$(s, 5): a = Val(Mid$(s, 6, 5)): b = Val(Right$(s, 5)): c = b - a
For j = 0 To c
.Cells(k, 1).Offset(j) = Format(p, "00000") & Format(a + j, "00000")
Next j
k = k + c + 1
End If
End If
Next i
.Select
End With
End Sub