Add vobsub (.sub) or .sup subtitles to existing DVD

[backoff34]

How can I import subtitles either vobsub (.sub) or .sup files into a DVD that I ripped? I have a DVD that has no english subtitles but have the vobsub file for english subtitles. Can I do this? I have heard things about using ifoedit, but cannot find a straight answer.

Thanks alot.