Sub test1()
Dim a As Workbook, b As Workbook
Dim aa As Worksheet, bb As Worksheet
Set a = Workbooks("Classeur1")
Set b = Workbooks("Classeur2")
Set aa = a.Sheets(1)
Set bb = b.Sheets(1)
bb.Range("C10:C13").Value = aa.Range("E10:E13").Value
bb.Range("C15:C20").Value = aa.Range("E15:E20").Value
End Sub
Sub test2()
Dim a As Workbook, b As Workbook
Set a = Workbooks("Classeur1"): Set b = Workbooks("Classeur2")
b.Sheets(1).[C10:C13].Value = a.Sheets(1).[E10:E13].Value
b.Sheets(1).[C15:C20].Value = a.Sheets(1).[E15:E20].Value
End Sub