adding subtitles to DVD format

[pitri]

I'm looking for a software or a sequence where I can plant subtitles (of any format) into a self made DVD video.
I know that extracting subtitles from DVD video is easy but I don't know if the other way around is possible.

[setarip]

I believe you can use IFOEdit together with VOBEdit to accomplish this...

[TheMatrix]

You can use the guide from here to do that