How do I import a file as a subclip?

In my panel, I have representations of clips and subclips from an external system. So far I can only see how to import an entire video into Premiere. Is it possible to import a subclip?

To import an entire video, I currently do the following:

Premiere.app.project.importFiles(["/path/to/file.mov"]);

I see the importFiles() takes a generic Object. Is there a struct that I can use for defining mark-in/mark-out points for this imported video?