how to add fonts to 5230?

Try this approach:

http://darlamack.blogs.com/darlamack/2007/05/changing_fonts_.html

There's also this (if Psiloc has a version for S60 5th Ed.):

http://shop.psiloc.com/en/Application,262312,Psiloc+Crystal+Arabic

Alternatively: Find a product code for Arabic firmware, change it on the phone, and update the firmware.