Converting MKV to DVD with selected audio

Okay, so I downloaded a torrent of Gundam Zeta episodes in MKV format, in dual audio. Now, I'd like to convert it to DVD, which I have done, however it only includes the Japanese audio track. I'd like to convert it to include both English and Japanese, or just English, how would I go about doing this?

I suppose XiliSoft can help you out there

I'll give it a shot, much appreciated. Thanks.