You just need to specify the remote host in your mysql_connect() command.
PHP Code:
mysql_connect('remote_host_or_ip', 'username', 'password');
Then from there construct a similar SQL statement to my example above. Just grab the different var name from $_POST such as $_POST['email'] (if that is your html field name), $_POST['age'], etc..
As far as dreamweaver, it will probably be saved as .html unless it's smart enough to see the php tags and rename. One problem with that is that [typically] the webserver isn't setup to parse .htm/.html files with the PHP processor. So you'll need to rename the html file yourself..
-r