Who can help me cause i´m lost?

I´ve got an existing original motion menu of a dvd. On the dvd i replaced a subtitle (dutch instead of dansk). So now i want to change the menu so that it shows the language (dutch) instead of the original (dansk).

What i´ve done so far:
- Demuxed de menu-vob with vobedit in cellid
- With virtualdubmod opent a corresponding vobcell and exported to image sequence.
- edited the bmp´s with photoshop
- remuxed de bmp´s with virtualdub to avi
- converted the avi with tmpgenc to m2v
- merged the m2v into the cellvob with vobedit
- joined the vobs back to an new menuvob

Everything fine untill here, the menu works.

The dvdmenu has also a subpicture with the action and selected buttons. I´ve already ripped them with subrip.
But how can i edit (guess with photoshop) this subpicture and get it back in the motion menu, including working highlight buttons.