There's not a setting to do that, but you can do it yourself if you know a little HTML or CSS. You'll simply need to copy the /modules/mod_sclogin/tmpl/login.php file to /templates/<YOUR_TEMPLATE>/html/mod_sclogin/login.php (creating any directories as necessary). Once copied, you can simply edit the file to re-arrange things as you need. There are a lot of classes on most elements as well if you would prefer to use CSS to re-arrange things.
Hope that helps, but if you need more info, just let us know,
Alex
Horizontal Login
