FWIW -
The Florida Department of Transportation (
FDOT) has wasted thousands, upon thousands of taxpayer dollars to create a utility they call
SheetSet Organizer (
which allows Microstation users to manage multiple DSTs for a single Civil 3D project ).
This utility is included with their
Civil 3D 2012 State Kit (
which has been in Beta for the past +/-6 years ), which Autodesk has willingly worked with them to expose APIs, develop code, and
even SP2.1, etc..
In any event... Use Reflection, or IlSpy to navigate
C:\FDOT2012.C3D\APPS\SheetSetOrganizer\SheetSetOrganizer.exe (
post-install)... To see how they use an external application to interact with SSM. Maybe that will present a rabbit hole for you to explorer.
HTH