Put the numbered files and the associated index.htm file in an appropriate folder.
You can manually name all the files or use a utility such as R-Name to automatically rename files with sequential numbers.
Edit 2 "index.htm" Pages
On a Macintosh, I use the free TextWrangler to do this.
1. Edit the "index.htm" within the "listening" folder.
To create the "index.htm" file for each listening -- that is the "index.htm" file that goes within the "listening folder," just make a copy of one of the "index.htm" files from one of the demos.
You need to change 3 things in the file: The Title, and the number of MP3 files (in 2 places).
2. Edit the main "index.htm" (The Menu Page).
The first time you'll need to change the TITLE of the Page in 2 places.
After that, all you need to do is copy one line of the menu, paste it where you want it, then edit it in 2 places, changing the FOLDER NAME ("lr") and the NAME OF THE ACTIVITY ("L and R Words")