I doubt it can be done but if you can borrow a disk it's quite easy. It doesn't have to be the original disk but you can assure the owner you need it only for this one purpose and won't be installing from it.
In Control Panel>Regional and Language, click the Language tab and tick the box to allow complex right to left languages because Farsi is one such. Borrow the CD and insert it then back in Languages, click the Advanced tab and find the relevant Unicode - do you think you'd get away with |Arabic? You're on your own from there on unless and Iranian comes along.