Boujour tout le monde.
Une macro, le doigt mouillé en l'air pour lancer le débat .
Sub Macro1()
Dim ref As Long, i As Long
Dim compt As Long
For i = 1 To 999
compt = compt + 1
ref = Val(Right(Cells(i, 1), 3))
If ref <> compt Then
Rows(i & ":" & i).Select
Selection.Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
Cells(i, 1) = "RA1B" & Right("000" & Trim(i), 3)
Cells(i, 1).Interior.Color = RGB(255, 255, 0)
End If
Next i
End Sub