Are you looking for a script to handle exchange rates or do you just want to convert the currency handling within the application to the Israeli Shekel?
Exchange would obviously be more difficult as you would need an API from an online service (preferably a world bank) that would keep the exchange rate up to date.
If you just want to handle the Israeli currency, you could easily just change out the US dollar symbol.
As far as language, are you talking about transliterated Hebrew or applying the actual Aleph Bet (Aramaic character set)? I would imagine the Aleph Bet could be applied with the correct charset identification and then going through and editing the content to your desire.