Please see my comment to the question. If this is what you mean, I'm not sure if formatting numbers to any certain culture will do the trick, most likely it will leave Arabic numbers Arabic, won't convert them to Easter Arabic. However, the conversion would be quite trivial. You can notice that Eastern Arabic numerals are ordered in the same way as Western (0 to 9) and take the code point range of 0660 to 0669, that is, they differ from Latin numerals, historically encoded as ASCII, only by constant shift ("0"-"9" take the range 0030 to 0029).
Please see:
http://www.unicode.org/charts/PDF/U0600.pdf[
^],
http://www.unicode.org/charts/PDF/U0000.pdf[
^].
Some code sample can be found here, you can check it up:
http://stackoverflow.com/questions/8926792/converting-numbers-from-western-arabic-digits-1-2-3-to-eastern-arabic-digit[
^].
Basically, you first format all numerals in Western style, obtain a string, and then shift the code points, but only for digits.
See also:
http://en.wikipedia.org/wiki/Arabic_numerals[
^].
—SA
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