I thought perhaps you were wanting the main theme music at the beginning or end of the movie. Well ... you could try extracting as ac3 & that will extract into the various ac3 channels (each in separate file.) Then take the left & right since the speech (or much of it) will most likely be in the centre channel. But there's no guarantee that will be the case. But then you need a program that can open & convert ac3 files. I have on the mac. I believe I read recently there's equivalent ones for windows. Google ac3 conversion. But separating dialogue from music if necessary is well ... is it worth the effort. What parts include dialogue could be replaced with parts that don't but are identical music sections if by chance the music repeats. Sounds like a big job for little reward.