Add subtitles to Original DVD

Hi I just get an original DVD, but it doesnt have spanish subtitles. I manage to found some subtitles in the web, and I was wondering if their is a way to add this subtitles to the dvd (making another dvd) without losing the menus and some other stuff.

I found some way to add the subs but you lose the menus in the process, I hope you can tell me a way this doesnt happen.

 

@freedy, I am not trying to pass the buck but if you post your question in the Subtitle Help Forum you may solve your problem.