This sample shows how a map can be called dynamically inside an Orchestration in Biztalk. This can allow for the map to be set at run time by setting a message context property or reading the value from the SSO or database. This can greatly reduce effort if a single business process is used for many different messages that need different maps.
This sample should work with BizTalk 2004 and BizTalk 2006.
Get more information from the original blog post on this topic: http://www.biztalkgurus.com/blogs/biztalk/archive/2005/08/28/Using-Dynamic-Transforms-_2800_Mapping_2900_-in-Biztalk-2004-Orchestrations.aspx