Using substr_replace() can be avoided by using substr() instead:
<?
$string = substr($string, 0, $position_needle).$replace.substr($string, $position_needle+$length_needle);
?>
This can be useful when you need to replace parts of multibyte strings like strings encoded with utf-8. There isn't a multibute variant for substr_replace(), but for php substr() there is mb_substr(). For more information on multibyte strings see http://nl3.php.net/manual/en/ref.mbstring.php