I think he/she means the opposite. The chapter headings are already "*". So that's what appears in the ToC. I believe they're looking for a way to use the physical individual chapter file (*.html) names to automatically fix the chapter heading and subsequently (I'm guessing) rebuild the ToC with the then corrected names.
Find and Replace with/without regex is the only possible way of automatically generating/changing those chapter headers (and thus the ToC) ... and to my knowledge, there's no provision for search and replace to access (or use) the underlying file's name in an F&R routine.
Although technically, you could
use regex on the toc.ncx file ... and as long as the play orders start with 1 and increment by 1 (you can automatically renumber them if not), you could capture the play order with regex and then use that number to build a new <text> entry:
<navPoint id="(.*?)" playOrder="(\d+)">\s+<navLabel>\s+<text>.*?</text>
<navPoint id="\1" playOrder="\2"><navLabel><text>Chapter \2</text>
(or something to that effect. I was just winging that example, so be sure to check the toc.ncx to make sure I didn't make some glaring error)
The expression could probably be made a lot cleaner, but I thought someone mentioned that there's issues with \K and look(ahead|behind)s in the latest beta.
NOTE: the above would fix the ToC, but do nothing to the chapter headings.