- substr: documentation ( source)
- preg_replace: documentation ( source)
<?php
$requestURL="http://localhost/neukundenbonus/?PartnerId=403&utm_source=bertelsmann&utm_medium=iframe&utm_campaign=Bertelsmann%20Club";
$url = preg_replace('/neukundenbonus/', 'https://www.lottowelt.de/lotto/online/de/lw/lotto-online-tippen.html', $requestURL);
$result = substr($url,1);
echo $url;
echo $result;