I think I should start from the basic.So I just create a combo box
in the excel sheet and want to add  a default name
list, "A","B","C".The user can choose the name from the list  or
enter a new name in the box. The entered names will be stored in a
column, say, column A.

firstly, I try to add the name list "A", "B", "C" to the downlist of
the combobox. I write the following codes:

Private Sub ComboBox1_Change()
ComboBox1.Value = "cc"
ComboBox1.AddItem "A"
ComboBox1.AddItem "B"
ComboBox1.AddItem "C"
End Sub

When I come back to excel sheet, there is no name in the downlist of
the box.Only when I change the text of the box, the list come out. I
think my codes create a run-time downlist. Could you tell me how to
create a default unchanged name list?