>How can I use ORDER BY Order_Item [ASC | DESC] [, ...]] to put all in descending order ?
>
>Do I need to create a numeric field to achieve it ?
>
>As I need the header on top I dont think alphabetic order will help

I don't know how you design your database.
So it is hard to me to answer.
BUT having HEADER record and details records in ONE table is NOT a good design for me (again, I don't know design and requirements).
You must MARK Header and detail records somehow, maybe having s field IsDetail L could help,

SELECT .....;
    FROM YourTable;
ORDER BY IsDetail, Order_Item DESC;
INTO CURSOR test