MAMP php file - how to run it from outside the server ( not local)

I have installed MAMP, and created a PHP file to the root of my installation ( c:\MAMP\htdocs) and to run I only use the url localhost/script.php in my browser. This works really niicely. My question is: Can I access this same file from the outside world through a browser (with my IP address)? Many thanks in advanced.