Create a custom template for a custom URL
You're on the right track. You just need to also create a file named page__mycustomtemplate.tpl.php (place it in your mytheme/templates directory). The starting point for this file should either be the page.tpl.php in your mytheme/templates dir (if there is one), or the one in mysiteroot/modules/system. Simply open one of these and save it as page__mycustomtemplate.tpl.php in your theme's templates dir. Then you can replace &lt;?php print render($page['content']); ?&gt; with your custom text/markup.