Dim OS As Worksheet
Dim OD As Worksheet
Dim DEST As Range
Set OS = Worksheets("Feuil1")
Set OD = Worksheets("Feuil2")
Set DEST = IIF(OD.Range("A1").Value = "", OD.Range("A1"), OD.Cells(Application.Rows.Count, "A").End(xlUp).Offset(1,0))
OS.Range("A1").CurrenRegion.Copy DEST