xml_get_XMLStrFromXPath($xpathObj,$path,$index=0)

/**
* Gets xml string from xpath object.
*
* @param object $xpathObj.
* @param object $path.
* @param int $index - defaults to 0.
* @return object.
*/
function xml_get_XMLStrFromXPath($xpathObj,$path,$index=0){
$nodes = $xpathObj->xpath_eval($path); // php 4
$nodeSet = $nodes->nodeset;
return isset($nodeSet[$index])?$nodeSet[$index]->dump_node():null;
}