lighttpd : How to add configuration without modifying lighttpd.conf file

To enable SSL/TLS on port 443 i have to add following in configuration file but i don't want to modify lighttpd.conf file and i want to modify start up script of lighttpd from where i can give below information in addition to lightttpd.conf as option to lightttpd process.

$SERVER["socket"] == ":443" {
    ssl.engine           = "enable" 
    ssl.pemfile          = "/etc/lighttpd/ssl/www.example.org.pem" 
}

Can anyone have any idea how to do this?