Hi, Werner. What you’re describing sounds a bit unique, and in that case I would recommend taking a look at the hooks available in Publisher (search it’s code for “active_hook”) and making a custom extension. It sounds like you would need the “publisher_set_language” hook.

You can try the eecms Slack channel to see if anyone is available to write it. I would take a look at it, but I just got finished with a small contract project and need to focus on other things right now so I can’t take on additional contract work. You might also be able to achieve this with JavaScript too. It would be a client side redirect, but you can get the browser’s language with JS and do a redirect based on whatever logic you need.

var getBrowserLocale = function () {
        if ('object' === typeof navigator) {
            return navigator.language || navigator.userLanguage;
        }

        return false;
    };