passing preg_replace backreferences to a function problem

[opern]

I'm having a huge problem with preg_replace and backreferences:

$name in the function leftimage is not what I would expect, e.g.

if $story ="foo [leftimage]front[/leftimage] bar";
then I would expect $name in the function leftimage to be "front" but it is "$1" instead, and hence the database query does not work.

So my question is how do you pass the backreference from the regexp to a function so that it can be used?
Thanks.

The code:

class parser {

function parsestory ($story,$id) {

	$patterns = array (
		"/\[b\]([ \w]+)\[\/b\]/i", # bold
		"/\[i\]([ \w]+)\[\/i\]/i", # italic
		"/\n/", # newline
		"/\[leftimage\]([ \w]+)\[\/leftimage\]/" # leftimage
		); 

	$replace = array (
		"<b>\\1</b>", # bold
		"<i>\\1</i>", # italic
		"<br>", # newline
		$this->leftimage('$1',$id)  # leftimage
		); 

	$story = preg_replace ($patterns, $replace, $story); 
	$story = stripslashes($story);
	return $story;
}


function leftimage ($name,$id) {
	$this->database->db_qry("SELECT id FROM images WHERE module='story' AND imageid=".$id." AND name='".$name."'", $full);
	$image = $this->database->get_data();	
	return "<img src=\"".$this->html->index("script=image&id=".$image[0])."\" align=left>";
}

}