The Outlook object model itself provides no method for setting a store as
the default delivery location. It might be possible with the Profman library
from Redemption (
http://www.dimastr.com/redemption/) but I haven't explored
that. The technique that Microsoft provides is to apply a .prf profile file,
which you can build with the Custom Installation Wizard or Custom
Maintenance Wizard from the Office Resource Kit.
Importing and exporting consists of copying data and creating new items. Any
Outlook programming book should cover those basic concepts. There is,
however, no automation for the Import and Export Wizard itself.