I18n for first user page/default page in multiple languages

Hi,
we’re starting with phpList using an installation on an own server (version v3.5.8).
I’ve read about the support of different languages in phpList, but still missing the chance of having the default page internationalized, the one that is shown to the unauthenticated users if no particular page was called up:

index.php

} else {
// If no particular page was requested then show the default
echo '<title>'.$GLOBALS['strSubscribeTitle'].'</title>';
echo $pagedata['header'];

The best solution would be to have a default value (taken from the user’s HTTP request) plus a drop down for changing the language. But always starting in one, fixed language and a drop down to change would be sufficient too.

Anyway, it seems, that there is no such option. Even the code as given above
echo '<title>'.$GLOBALS['strSubscribeTitle'].'</title>';
is always using the same value (in this case the one from german.inc), no matter what OS language and browser language are used.

And not using this page doesn’t really makes sense in my opinion as it allows to do, what users are likely willing to do (change settings, unsubscribe, contact the administrator).

Any ideas about how to solve this? Maybe there are workarounds (not using the default page) to have a smooth multi language UI for the users?

Thanks in advance
Howie