Option Explicit
Sub Code_insérer()
Dim c As Range, cc As Range
With Application: .ScreenUpdating = False: .Calculation = xlManual: .EnableEvents = False: End With
For Each c In Range("a2:a1000000").SpecialCells(xlCellTypeVisible).SpecialCells(xlCellTypeConstants)
Set cc = [a:a].Find(c)
If Not cc Is Nothing Then c.Offset(, 1) = cc.Offset(, 1)
Next
With Application: .EnableEvents = True: .Calculation = xlAutomatic: .ScreenUpdating = True: End With
End Sub