Does anyone know a command line tool which allows cutting idx/sub and/or pgs subtitle files?

I already wrote a small tool to write .srt/.ass/.ssa subtitles (if some one wants to try it, see here), but these are easy to cut since they are text based.

What I'm looking for is a (small) command line tool which accepts:
  • a subtitle file (idx/sub, pgs)
  • a list of cuts (from-to,...); I'm flexible regarding the format

and that outputs a cut stream.
I suspected that this wouldn't be to hard to write if one knows the idx/sub, pgs file structure, but since I haven't found anything via google&co I ended up here.

-> Is there something like this out there?

Cu Selur

Ps.: would be great if there were linux&windows versions for this tool, but Windows only would be cool too.