Sub Ajout()
Dim endCol1 as Long, endCol2 as Long
endCol1 = Range("C1").End(xlDown).Row
With workBook("monFichier2").workSheets("Feuil1").Range("A1)
endCol2= Range("A1").End(xlDown).Row
.range("A1:A" & endCol2).select
.Selection.Copy
end With
Range("C" & endCol1 + 1).Paste
End Sub