I don't know if my question is silly, but if it is, at least it will be a moment of fun.

So, I was wondering whether it exists for Blu Ray Discs a tool like DVDsubEdit, which allows us to modify the locations of one sub on the screen.

For example, image all subs are placed at 50 pixels from bottom, and at one particular moment, I would like to have one of the subs be placed with a bottom margin of 100 pixels.

Do you if it is possible, please?