Dim Plage As Range
Dim Cel As Range
With Worksheets("Feuil1")
Set Plage = .Range(.Cells(1, 1), .Cells(.Rows.Count, 1).End(xlUp))
End With
For Each Cel In Plage
If Cel.Value Like "*a*" Then Cel.Value = "1 " & Cel.Value
Next Cel
End Sub
Sub lulu()
For lig = 1 To Cells(Rows.Count, 1).End(xlUp).Row
If Cells(lig, 1).Value Like "*a*" Then Cells(lig, 1) = 1 & Cells(lig, 1)
Next lig
End Sub