-R [bind_address:]port:host:hostport

ssh -R *:8080:localhost:80 -N root@website.com
or
ssh -R 0.0.0.0:8080:localhost:80 -N root@website.com
or
ssh -R [::]:8080:localhost:80 -N root@website.com

Note that if you use OpenSSH sshd server, the server's GatewayPorts option needs to be enabled (set to yes or clientspecified) for this to work (check file /etc/ssh/sshd_config on the server). Otherwise (default value for this option is no), the server will always force port bound on the loopback interface only.