How to create a newsletter subscription form using Uniform & Mailchimp?

I was thinking about the router because the site uses the panel and I’d like the panel users to not see these pages (newsletter/subscribe)… and possibly avoid its destruction in the near future by untrained panel users. I’m also not saving any infos there… just communicating with mailchimp.

Is it still doable using the router? I was actually adapting the technic below which @texnixe taught me a while ago. But not sure it’ll work with POST requests.

c::set('routes', array(
  array(
    'pattern' => '(:all)/subscribe',
    'action'  => function($uri) {
      tpl::load(kirby()->roots()->templates() . DS . 'newsletter.php', array('uri' => $uri), false );
    }
  )
));

So all the logic from @bnomei 's wrapper goes in the Uniform action, ok got it.
Then how’d would I call it? Since it will come from several different URLs I can’t use the template controller (the question above). Using the router? Using call_user_func()?

I’m trying to see the outline of the subscribe action… to understand which script calls what and how to handle the replies from the API.