Minor Extra Requirement Needed in a Wordpress Plugin

I have this free plugin installed on my website (WooCommerce Extra Charges To Payment Gateway - [login to view URL]). It charges a fee based on payment gateway used, for example adding a 3% charge on the order total if the customer chooses to pay with PayPal. I have that done fine through the plugin. However what I need is to charge the extra 3% for using paypal on CERTAIN countries only. For example charge 3% for using Paypal to customers from the US and UK. Don't charge extra 3% for using Paypal to customers for all other countries' customers. Is there anyone who is able to help me here? I won't pay much for this as I believe it is a simple task for a coder. On a side note I need this ASAP as I am launching my store within 2 days. Looking forward to hear from you guys.