To add an extra subtitle button to an existing menu, you need to reauthor using some menu authoring software.

Here are the general steps:

1. Extract the menu background to a bitmap via 'Export frame' in Preview window of DRMP.
2. Extract the subpicture bitmap for the button highlight with Subrip.
3. Edit the menu background and subpicture bitmap with some picture editor, e.g. Photoshop. If using Photoshop, the menu background must be saved as 24-bit OS/2 bitmap; subpicture as 4-bit bitmap.
4. Author these 2 modified bitmaps with some authoring software. I use DvdLab Pro and DVD Maestro.
5. Replace the original menu with the modified one in DRMP via 'Replace block'.
6. Change the button command for the new button(s) to activate the desired subtitle. Follow the button command format from the original buttons.
7. Test in debugger to see if everything's working.
8. Test in software player to see button highlight when selected/activated.
9. Once satisfied, burn away.

The only time consuming process is step 3, maybe 4 depending on how familiar you are with the software.

Some authoring software include freewares like DVDAuthorGUI, Gui for DVDAuthor (GFD), DVDStyler; commercials like DvdLab (Pro), DVD Workshop, NeroVision Express, TMPGEnc DVD Author, etc.

Similar topic:
http://www.cdr-zone.com/forum/viewto...?p=11574#11574