Installing Condigniter in subfolder but setting multilanguage as in root

Note: Sorry for adding more information on another post, but I was not able to edit my first post still waiting for moderation.

The update:

I am using this code on the .htaccess file, on the root folder, to try to do the trick:

Code:

RewriteRule ^es/software/$ /software/index.php?lang=es&%{QUERY_STRING} [L]

It almost works, because now is reading the CI installation but it shows a 404 with this message: `Controller or its method is not found: App\Controllers\Es::spinner`

Like if it is trying to find a controller on the wrong controller and method.