You can use a htaccess file to set the Microsoft-Server-ActiveSync dir, if you are on a shared Webhost and dont have access to the Apache Configuration:
RewriteEngine on RewriteBase / RewriteRule Microsoft-Server-ActiveSync(.*) /var/www/user/html/oczpush/index.php$1 [E=ACTIVESYNC:true,E=REMOTE_USER:%{HTTP:Authorization}]