Payment option based on location

hello ,

I use payment method Cash on delivery for my website But i stay in India and cod is limited to limited pin codes. Now i want payment option CoD to be shown only if a person belongs to those pin codes (i.e - Cash on delivery payment method got to be shown only if person has entered among the pin codes i have in his shipping address). This I was able to to easily for my another website which runs on opencart but am finding it really tough and hard to make this work in cs-cart. Any help shall be highly appreciable.