another way to save all subs and add new one?

[globe]

hye @ all
im searching another way to do this:
https://forum.videohelp.com/viewtopic.php?t=275603
i think its called multi-pgc (fix me if i worng)
basicly i want to rip all subs and add new one but use DVD-LAB.
i heard i can do it like this: "add new video and there i add the pgc"
but i cant understand from this nothing
someone can help me?
tnx.