A VBA programmer can open a DGN file using two methods: OpenDesignFile and OpenDesignFileForProgram. This blog attempts to clear up confusion between the two, and which one to use.
Prefer OpenDesignFile to OpenDesignFileForProgram! OpenDesignFile opens a DGN file in the same way that a user would open a DGN file. Everything you expect to be available is available: level libraries, text styles, reference…
This blog provides some code snips that demonstrate how to use DgnEC Native and Managed API’s for following: