A combobox control works much like a picklist, in that it presents a number of selectable values to be stored in that control.  You can set available values at development time using the items property of the control, but for greater flexablility, you can populate the control at run-time as well.  For this example, we'll populate a combobox with a distinct list of Account Type values:

 First we want to clear the combobox of existing items, so we aren't adding duplicates:

ComboBox1.Items.Clear

Next, we'll create a recordset containing a distinct list of account type values.

Dim objRS

With objRS

   Set objRS = Application.CreateObject("ADODB.Recordset")
   .CursorLocation = adUseClient
   .CursorType = adOpenStatic
   .LockType = adLockOptimistic
   .Open "select distinct type from account", Application.BasicFunctions.GetNewConnection

Finally, we loop through the recordset, adding each returned item in turn.

   While Not (.BOF or .EOF)
      ComboBox1.Items.Add .Fields("TYPE").Value    
      .MoveNext
   Wend
   .Close
End With

Set objRS = Nothing