To do this on your web site would require some custom PHP script, as follows (example for list 1):
<?php$link = mysql_connect('localhost','USERNAME','PASSWORD');mysql_select_db('DATABASE,$link);$urows = mysql_query("select count(*) from lm_users where list = '1'");list($numusers)=mysql_fetch_row($urows);echo $numusers;?>
This code can be inserted wherever you want the counter. Replace USERNAME, PASSWORD, and DATABASE with your ListMail MySQL access info (same as config.php).
If your pages cannot run PHP, possibly because your files are named ".html", you will need to add a file named ".htaccess" to the directory your page is in. Since you can't create this filename in Windows, edit the file as "htaccess.txt", upload it, then rename it remotely.
The file should contain the following:
AddType application/x-httpd-php .html
Hope that helps!