Bonjour,
une proposition via une macro
Sub aexpedier()
Set wsc = Worksheets("sheet1") 'feuille des commandes
Set wse = Worksheets("sheet2") 'feuille des expéditions
Set wsr = Worksheets("sheet3") 'feuille résultat avec les commandes non expédiées
dlc = wsc.Cells(Rows.Count, 1).End(xlUp).Row
dle = wse.Cells(Rows.Count, 2).End(xlUp).Row
dlr = 1
wsr.Cells.ClearContents
wsc.Rows(1).Copy wsr.Cells(1, 1)
For i = 2 To dlc
Set re = wse.Range("B1:B" & dle).Find(wsc.Cells(i, 1), lookat:=xlWhole)
If re Is Nothing Then
dlr = dlr + 1
wsc.Rows(i).Copy wsr.Cells(dlr, 1)
End If
Next i
Set wsc = Nothing
Set wse = Nothing
Set wsr = Nothing
Set re = Nothing
End Sub