I don't think you can add the range, I think you need to add each item one at a time . . .

VB Code:
  1. Dim c As appExcel.Range
  2.     appExcel.Workbooks.Open FileName:="C:\Program Files\LFhost\Maccrystal01.xls"
  3.     appExcel.Worksheets("dblisting").Select
  4.     For Each c In range("a1:a255").Cells
  5.         cmbbx.AddItem  c.Text
  6.     Next c