Hi @rage, you first have to configure the exporter plugin then Load the document/ Merge it.
Cinema 4D will automatically use the settings you defined in the plugin.
You can find examples of the procedure in our github repository.
Finally, symbols for supported exporter/importer are exposed in this page of the Python documentation.
Unfortunately, there is no area describing each symbol for each exporter in the python documentation, but you can find them using the search engine in the C++ documentation. (I linked you the C++ symbols of OBJ, import)
If you have any questions, please let me know.
Cheers,
Maxime.