To import a .dgn file to a .dwg file:
- Load the DGN import TX module.
- Create an importer instance.
- Set the host application services object (to create a new database, etc.).
- Set import parameter values. Set the path to be imported.
- Do the importing (call the import() method of the importer).
For more details, see the Importing .dgn Files to .dwg Files topic and the DGN Import sample application at Drawing/Examples/ExDgnImport.