Im new to this VB stuff so excuss me if any advice I give is crap but...
If you have VB 6 ADO allows you to fill a combo box without the need for any coding. I used a dataCombo because that was the only one that seemed to work.

Create a DataEnvironment, a ADO Connection, a SQL Command on tables required. In the properties of your datacombo you should now be able to select from these.

Datasource should = DataEnvironment
Datamember should = SQL command created
Datafield should = the field you want to place in combobox
Rowsource & Rowmember should = same as Datasource & Datamem
Listfield should = Datafield
Combo (Style) should = 2 dbcDropdownlist

Lets us know how you went.

Cheers Jonny