I would like to add function {GUEST_COUNTRY}in wire_transfer_email.html. Now I added j00605wire_transfer.class.php code $output['GUEST_COUNTRY']=$guestDetails->country;and we do not display the full name of the country.

what is displayed? Just the country code? If yes, try:

$output['GUEST_COUNTRY']=getSimpleCountry($guestDetails->country);

Thanks Piranha