I'd suggest:

Sub M_snb()
   For j = 0 To 1
     With Sheet1.OLEObjects.Add("Forms.Combobox.1", , , , , , , Columns(10).Left, Rows(4 + 2 * j).Top, 60, 18)
        .Name = "C_" & Format(j, "00")
        .Object.List = Split("A B C D E F G")
        .Placement = 3
     End With
    Next
End Sub