I still can't figure this out so I'm going to be a little bit more specific.
I'm trying to copy some of my favorite stories from fanfiction.net. WinHTTrack
does not detect the links because to get to them you have to click on a java
box so, in a way, the links are hidden. However, the chapters are all saved in
a series of directories. For example, chapter 6 is in
<http://www.fanfiction.net/s/****/6/> but WinHTTrack can only detect
<http://www.fanfiction.net/s/*****/1/>. So, how do I make it so that it can
"spider" up to, say, directory /99/ and download the links which return a
result.

If you've already answered this, I'm sorry but I didn't understand.