I was thinking of something like this:

URL a user enters:

http://your_server/page1.html

mod_perl maps this into:

http://your_server/cgi-bin/myscript.pl?temp=page1.html

or even:

http://your_server/cgi-bin/myscript.pl/page1

(this is how it will look if you use CGI::Application. I suggest get this working first, then add a .htaccess file in your cgi-bin directory to add the mod_perl mod_rewrite stuff afterwords.)

The script reads in template "page1.html", figures out the counter value, inserts it, and displays the page.

All the template files should be in a special directory, not under the document root, so there's no way a user can point their browser to the "real" page1.html.

update: corrected typo