Url: http://yoursite.com/news/000001.html

Set up a 404 error handler:

<Directory /home/httpd/news>
    ErrorDocument 404 /generate-news.php
</Directory>

generate-news.php:

<?php
    $id = basename($_SERVER['REDIRECT_URL'], '.html');

    /* Generate the HTML */
    include "/home/httpd/news/generator.php";
    $html = generate_html($data);

    /* Show the page */
    echo $html;

    /* Store the page for later use */
    $fp = fopen(sprintf("/home/httpd/news/%06d.html", $id), "w");
    fputs($fp, $html);
    fclose($fp);
? >