Actually, I am in much need of something similar, however, I have located a superb example of the desired effect.
http://forum.persiantools.com/
If you can't be bothered to register, just use my account.
Username: Logicus
Password: lookhere
Log in, go to User CP, (and after changing to English if you so wish), look at the profile editor. I don't care what you do, as I don't read Persian, and I don't intend to learn.
However, I'm trying to create the same effect for Arabic on
www.lexiglobal.net/forums, a board still in production that I hope will have several languages.
Unfortunately, although I have installed Arabic, checked the rtl settings, and allowed for an Arabic font, I can't make Arabic textboxes work at lexiglobal. The four cases do not show up in there respective places relative to the word, and the right to left text is incredibly buggy.
Help is much appreciated!