ну тогда вот:

<?php

$code = '<td align="right">Текст бла бла press "right" button</td><img src="/right.gif" /> текст текст трам парам';

$code = ereg_replace("\-\"right\"", " <strong>right</strong> ", $code);
$code = ereg_replace("[^=]\"right\"", " <strong>right</strong> ", $code);
$code = ereg_replace("[^=]\ \"right\"\ ", " <strong>right</strong> ", $code);
$code = ereg_replace("\-\"right\"\-", " <strong>right</strong> ", $code);

print $code;

?>