Using a regex on html is like eating wild mushrooms that you found in the woods. There are times where it’s appropriate and safe, other times where it’s completely insane and possibly deadly, and it takes considerable experience to know how to tell the difference.
It can be done with simple regex of the kind proposed in various answers there iff the html is known to be limited to the subset of html where that sort of thing can easily be made to work. The question does not tell us whether or not that is the case, so everyone is free to make their own assumptions and argue as if they know what’s going on.