Hunspell or MS Word spell checker? Which one is better for Persian Language?

Hi

Which one of the spell checkers is more flexible with the Persian language that is written from right-to-left? Personally, I use Hunspell in Trados and MS Word in MS Office, especially in MS Word. I can't feel any difference between these two, and both recognize correct words as mistakes and can't see which one is better to work with the Persian Language. Does both similar or of them is better to work with some languages like Persian? Which one is more fit with Trados Studio?

Thanks

Masoud