preg_replace
RewriteCond %{REQUEST_FILENAME} /(.*)-f([0-9]*).html
<?php
$patterns = array (‘/(19|20)(\d{2})-(\d{1,2})-(\d{1,2})/’,
‘/^\s*{(\w+)}\s*=/’);
$replace = array (‘\3/\4/\1\2′, ‘$\1 =’);
echo preg_replace($patterns, $replace, ‘{startDate} = 1999-5-27′);
?>