将RSS源从php转换为xml

The code below is a PHP generator that generate a simple web page in PHP with just one feed from my RSS URL. This URL has around 60 feeds.

I would like to generate a XML RSS with just one feed in random mode. Is this possible?

<?php

    function load_xml_feed($feed){
        global $RanVal;
        $i= 1;
        $FeedXml = simplexml_load_file($feed);
        foreach ($FeedXml->channel->item as $topic) {
            $title[$i] = (string)$topic->title;
            $link[$i] = (string)$topic->link;
            $description[$i] = (string)$topic->description;
            $i++;
        }
        $randtopic = rand(2, $i);
        $link = trim($link[$randtopic]);
        $title = trim($title[$randtopic]);
        $description = trim($description[$randtopic]);
        $RanVal = array($title,$link,$description);
        return $RanVal;
    }

    $rss = "http://syncds.boxip.com.br/feed?code=24C165DB04";
    load_xml_feed($rss);
    $link = $RanVal[1];
    $title = $RanVal[0];
    $description = $RanVal[2];

    echo "<h1>".$title."</h1><h2>".$link."</h2><p>".$description."</p>";

?>

Thank you guys.