Sorry for the late reply, sort of forgot about it.
Browsed through some of those links... Combining one and two things, this is what I came up with:
<?php
$redir = $_GET['url'];
header("Refresh: 10; url=$redir");
?>
Seems easy enough to me!
(But yea, for a PHP noob like me.. woopie :p)
Going to test it and BRB!
Edit: Works perfect!
Put the code above in a snippet named Redirect, placed the tag on the page with the dislaimer and linked to it with www.mydomain.com/out.php?url=
http://www.modxcms.com
Thanks for all the help!