Currency Based on Zone

Hi,

Open Cart Default currency is INR (Rs.)
During testing, when I created international user (from USA) , while checking out, I got Error from paypal module
denominated in WS_Error_XClick_Pref_Foreign_Currency.

I Understand cause Paypal is not recognising symbol Rs. I have changed the site default currency to USD

Need feature, where currency is selected based on Zone.