Although you realized that you didn't need it in this situation, you can simply call the business object's SetAlias() method to change the InitialSelectedAlias. As Alex suggested, it's usually best to have separate business objects for this purpose, but there are definitely times when you have a special circumstance that requires switching aliases dynamically.
Regards,
Kevin McNeish Eight-Time .NET MVP VFP and iOS Author, Speaker & Trainer Oak Leaf Enterprises, Inc. Chief Architect, MM Framework http://www.oakleafsd.com