Selectively grabbing subtitles

I'm new to the list, so please excuse me if this question has been
asked before.  I searched through the archives, but couldn't narrow my
search down.  I either got hundreds of results, or none at all.

I would like to know how to get the subtitles only for dialog that
isn't English.  For instance, in a science fiction movie where alien
characters are speaking their native tongues I want that subtitled but
nothing else.  Every way I've tried it I end up with subtitles for all
the dialog.  Basically, I want to know how to make it behave like the
DVD does.  What am I doing wrong?

Thanks,
Kurt Forsberg