Populating a ComboBox at Runtime

Hi all. On a customized form, is it possible to populate a combo box
(UltraCombo or just Combo) with several values on formload? This is
typically handled in VB.NET with ComboBox.Item.Add("First Item");
ComboBox.Item.Add("Second Item"); etc. This function does not appear to
be available within Vantage. Is there something equivalent or another
way to load a list of values at runtime into an UltraCombo box, without
binding to a UD table? Thanks.