protected function getNode( $nodePath )
	{
		$pathNodes	= explode( "/", $nodePath );
		$xmlNode	=& $this->xmlTree;
		while( $pathNodes )
		{
			$pathNode	= trim( array_shift( $pathNodes ) );
			$matches	= array();
			if( preg_match_all( "@^(.*)\[([0-9]+)\]$@", $pathNode, $matches ) )
			{
				$pathNode	= $matches[1][0];
				$itemNumber	= $matches[2][0];
				$nodes		= $xmlNode->getChildren( $pathNode );
				if( !isset( $nodes[$itemNumber] ) )
					throw new InvalidArgumentException( 'Node not existing.' );
				$xmlNode	=& $nodes[$itemNumber];
				continue;
			}
			$xmlNode	=& $xmlNode->getChild( $pathNode );
			continue;
		}
		return $xmlNode;
	}