You might consider this approach.
Rip the files to AVI's then you need to create an SRT file with the subtitles. (whatever language)
Here is the hard part you need to run the video through FFDSHOW and encode it to an AVI, I don't believe VobSub will let you do that. However there is an AVI encoder out there that will I just can't remember it's name. Once you have it encoded to an AVI of the RIGHT format that is one Sony's FMV utility will accept you have to use Sony's distributed tool to convert it back to an FMV/MOV. It gets more exciting in a moment. To stuff it into an ISO the data must be inserted correctly and exactly over the original data I'm not sure what to do with the ADPCM data there, I would insert the video data in the correct sectors format and leave the ADPCM sectors alone myself.
Now this is a VERY non trivial deal so unless you know how to program your own tools to insert it into an ISO... you can't do it. You don't need to specifically know ISO9660 format data just how to use it. There was a guy named Pixel who made some LUA (script format) based ISO tools that may do the job. Again this requires programing to use however.
Cyb
