Does any body know how to migrate from PHP 5.2.xx to 5.3.xx, using a hosted ISP?

[DarkFellow]

The ISP site itself has PHP version 5.2.1 and I need version 5.3.x. to run the version of moodle I'm presently employing. Can I do an installation within my domain and make a configuration file to tell Moodle to use my PHP installation??