Comment intégrer un script php dans MODx ?

echo"<!--~~~CrawlTrack~~~~~~~~~~~~~~~~~~~~-->\n";
$crawltsite=1;
include("/xxx/crawltrack/crawltrack.php");
echo"<p><a href=\"http://www.crawltrack.fr\">
<img src=\"http://www.jauraisduluidire.com/crawltrack/images/nologo.png\" alt=\"CrawlTrack: free crawlers and spiders tracking script for webmaster - script gratuit de détection des robots pour webmaster\" width=\"1\" height=\"1\" style=\"border:0\"/>
</a></p>\n";
echo"<!--~~~CrawlTrack~~~~~~~~~~~~~~~~~~~~-->\n";

$output = "<!--~~~CrawlTrack~~~~~~~~~~~~~~~~~~~~-->\n";
$crawltsite=1;
include("/xxx/crawltrack.php");
$output .="<a href=\"http://www.crawltrack.fr\">
<img src=\"http://www.jauraisduluidire.com/crawltrack/images/logo9.png\" alt=\"CrawlTrack: open-source crawlers and spiders tracking script - script open-source de détection des robots\" width=\"80\" height=\"15\" />
</a>\n";
$output .="<!--~~~CrawlTrack~~~~~~~~~~~~~~~~~~~~-->\n";

return $output;