Unicode SEA script find/replace utility?

[navako]

I've been searching around for some combination of software and
(apple-)script to allow transliteration *between* SEA Unicode scripts --of
course, the same setup could easily enough convert romanized text to and
from SEA text.

Has anyone found a decent solution for this?  In my case, I'm interested in
switching Pali text between Khmer and Burmese (theoretically, I would also
want to try to get it working with Sinhalese) scripts.  I'm sure someone
must have a comparable problem switching between modern Thai and Khom (or
modern Khmer).

I'm using a Mac (OS10), but any information for any platform would be
welcome.

Eisel M.

--
A saying of the Buddha from http://metta.lk/
For the sake of others' welfare, however, great, let not one neglect one's
own welfare. Clearly perceiving one's own welfare, let one be intent on
one's own goal.
Random Dhammapada Verse 166