The HTML doc has anchor links to other places within the doc. You can create such links in word but the html import doesn't keep them. OpenOffice seems like it might work. I tried the newest one which opens HTML ok in the HTML editor, links work and everything. Apparently it's possible for OpenOffice to convert to word but maybe some import preferences need to be checked. When I try this on my Mac (with newest LibreOffice), any preference changing crashes the app. Maybe I could hand the HTML file to someone and they could give it a try? Just convert it to a Word Doc and see if the links are ok.
Not sure about Amber ePub to Doc; there's no demo to try.
edit: was able to get OpenOffice to works. Some links work, some don't. So still looking. Anything that let me get from HTML to (eventually) Word with anchor links. Even if it needs another app or many apps in the middle. InDesign, who knows..