For a RowSourceType of 2,3 or 6

SELECT DISTINCT mycombofield ;
 FROM mytable ;
 INTO CURSOR mycombosource

For a RowSourceType of 5

SELECT DISTINCT mycombofield ;
 FROM mytable ;
 INTO ARRAY amycombosourcearray

If using RowSourceType of 0, do one of the above and AddItem() or AddListItem() for each row.

HTH