$routes->addRedirect with regex?

The addRedirect() method does not support replacement.

You can use this hack

PHP Code:

$routes->any('subdir/([a-z\-]+)/([a-z\-]+)-(\d{2}-\d{4}\.\d{2})\.html', function(){
    $router = Services::router();
    $request = Services::request();
    $path = preg_replace(
        '#^' . $router->getMatchedRoute()[0] . '$#u',
        $router->getMatchedRouteOptions()['redirect'],
        $request->uri->getPath()
    );
    throw new RedirectException($path);
}, ['redirect' => 'subdir/$1/$2-$3']); 


Or create your own class that extends the Router class and implement a replacement in it.
Or post a new issue on github or PR with fixes or comment in the documentation about the inability to use regex.