How to use a predefined tracking number for placing an Order?

Commerce Server 2007: How to use a predefined tracking number for placing an Order?
http://blogs.msdn.com/b/nihitk/archive/2006/06/21/cs2007-predefined-trackingnumber-for-order.aspx

HOW TO AVOID DUPLICATE ORDERS NUMBERS IN COMMERCE SERVER

http://microsoftblog.co.in/commerceserver/how-to-avoid-duplicate-orders-numbers-in-commerce-server/