Does iPlanet 4.0 and Sun One Webserver 6.1 support mod_rewrite? If yes, how to enable mod_rewrite?

I am planning to use Code Igniter/ Zend framework for PHP. But, the .htacess files contain mod_rewrite which doesn't seem to be working on Sun One Webserver. Is there anyway i can bypass using the mod_rewrite in these webservers?