From the documentation:

> The core export format of novelWriter is HTML5. You can also export the entire project as a single novelWriter Markdown-flavour document. In addition, other exports to Open Document, PDF, and plain text is offered through the Qt library, although with limitations to formatting.

So it seems like it can export to Open Document, which seems to be well-supported[1]; including Microsoft Office support.

[1]: https://en.wikipedia.org/wiki/OpenDocument#Application_suppo...