If rowsourcetype = 0 put this in init event of the combo control
This.List(1,1) = "Display1Column1" &&1st Row Column1
This.List(1,2) = "Display1Column2" &&1st Row Column2
This.List(2,1) = "Display2Column1" &&2nd Row Column1
This.List(2,2) = "Display2Column2" &&2nd Row Column2
Etc.
Combo Bound property value depends on how you want it (base on the no. of column).
Remember the first column is always the first display text.
Bound property can be change up to the no. of your columns on the RowSource property (Whether from SQL, ALIAS, ARRAY etc.)
Base on example above. If I set Bound = 2, the value to be stamp on the controlsource is values on column no. 2 but the display value is always 1 if you columncount is 0.
In order to have a default upon execution of the apps add this to init event.
This.Value = "Display1Column2" but the displayvalue is still "Display1Column1"

Hope this helps.