Subtitles & Dual files

I don’t know how I can attach subtitles to files and how I can change the language on a file that is a dual one?
There is anyone who can help me?

Thank you

to get a subtitle to play - it has to have the same filename as the AVI file - and be in the same folder - but this is ATVFiles I am talking about.

No idea about dual subtitles - i can never get them to change…

Thanks about the subtitles.
I think I din’t explain very well.
There were two questions.
I was asking how to change audio in a dual video & audio file…

Anyway thanks for your answer

First, to add subs there is a fine little app called muxo. pretty much self explaining.
Second, giving you have atv 2.3, press and hold play on the remote. you get kind of a menu where you can switch audio tracks & subs (I think, subs have to be embedded, see first).