Make sure you have the domain pointing to the correct web server (or if its local, you can use the hosts file).

Then make the web server work for that domain (i.e. if you have an existing laravel install working on www.x.com and you just want to enable another domain for it, if using apache use the "ServerAlias dev.x.com" under the "ServerName" directive).

Then that's it. The site will work for that domain. Laravel doesn't require specific domain setup to actually work.

This is on a actual server not local, as a subdomain for example myapp.domain.com

You should point a registered subdomain to your server location, and then configure the virtual host for that subdomian to point to the /public/ folder in your laravel install. You shouldn't be trying to change the URL/domain with htacess files really.

See in this site.

http://www.raphaelfiga.com/desenvolvimento/instalando-configurando-virtualhost-apache-windows/