bonjour,
une proposition sur base de ce que j'ai compris
Dim a(2), c
Sub aargh()
c = 0
dl = Cells(Rows.Count, 1).End(xlUp).Row
Columns(2).Clear
combine dl
End Sub
Sub combine(dl, Optional n = 1, Optional s = "")
For i = 1 To dl
a(n) = Cells(i, 1)
If n = 2 Then
If a(1) <> a(2) Then
c = c + 1
Cells(c, 2) = a(1) & "-" & a(2)
End If
Else
combine dl, n + 1, s
End If
Next i
End Sub