Convert idx+sub timecode from PAL to NTSC?

[Chetwood]

Subresync can sync the timecode of idx+sub but how do I convert the whole subs from PAL to NTSC? SRT files can be done in Subtitle Workshop but what about these?

[BigCondor]

Use Vobsub cutter to change the frame rate of idx+sub. Alternatively, you can also use Subresync to adjust the first and last subtitle and the rest will be adjusted accordingly if you know the position of the first and last subtitle.

[Chetwood]

Vobsub cutter did do the trick, thx.