Well, you’ll first need the full version of NNW, that one that supports AppleScript. They offer a free 30 day trial on their site. You’ll also need to grab the script Subs to HTML and put that in the NNW scripts directory. Once it’s there there are two things you can edit:
I have them set to “h3” and “h4” respectively. However, they are easy to change in script editor. If you do change them, make sure you compile the source again and then re-save.
Once you’re all set, just run it from the scripts menu and your output will show up in Text Editor. So, there ya have it. Pretty simple. I wrote this simply for personal use but feel free to edit this so it will fit your needs.
Source: Subs to HTML