The book had already been written in MS Word and I'm trying to convert it to kindle format. I'm aware of Sigil and tried opening the html using it, but there were some other issues involved. But since the document is already essentially finished, I don't think it's necessary.
The characters were inserted in Word as part of the normal character set there. I know little about how characters work. Looking at the html file, the check, for example, is showing:
<span style='font-family:"MS Mincho"'>✓</span>
EDIT: That's "& #10003;" between the span tags.
Is there another way to put the characters here?
To reiterate the problem, when I move this html file directly into the previewer it displays fine, but the ToC is not recognized. Jumping through the aforementioned hoops to create a prc was intended to be a solution for the missing ToC. And it was, the ToC is recognized, but then the characters don't display.