Per Directory PHP Value??

[ephigenie]

you can use .htaccess however not for manipulating php settings as php is executed over fastcgi per default.
This ensures that php is executed only with the rights of the current user ( domain ) .
.htaccess & php settings require mod_php however which does not provide these security restrictions.

So you'll have to change this on a per domain basis below /var/www/fcgi is a php.ini for every domain.