It depends what you've got available on your server. You can do it with HTML-only with an iframe:
| HTML |
| <marquee><iframe src="news.html" height="20" width="100%"></iframe></marquee> |
Personally, I'd prefer to avoid the iframe and use server-side scripting, e.g. PHP:
| HTML |
| <marquee><?php echo file_get_contents('news.html'); ?></marquee> |