It's not going to work in PHP; it's a CFML tool not a PHP one.
CFML is an alternative to PHP, but it uses different syntax and code
written for a CFML engine would need modifications to work on a PHP
server.
PHP already has its own regex functions, documented here:
http://www.php.net/manual/en/ref.pcre.php
Did something lead you to believe cfRegex would work with PHP?