Conditional logic on country field

We have an dropdown select list of countries in our form, and we want to be able to work out the region and pass that to a hidden field in our form. So if someone chooses a European country, the hidden field is populated with the value Europe. Thinking it’s easily done with conditional logic, but can’t find a way to bulk add a list of countries, and seems I will have to enter each country name individually. Any ideas?