Help converting a Dual Audio File!

[hoboX10]

(Sorry, I am not exactly sure where this goes)

Alright so I download a Dual Audio (Jap/Eng) .mkv video. How do I make sure that when I convert it, it will use the English audio and not the Japanese?

[RunningSkittle]

http://forum.doom9.org/forum-rules.htm

[hoboX10]

http://forum.doom9.org/forum-rules.htm

Please explain how this helps me.