Change currency on the currencies bar based on GEO tagging

Hi Guys.

We have enabled 2-3 currencies on the currencies bar. How can we configure, what currency should be shown default, based on what geo tagging. E.g. We would like the bar be default loaded with the DKK currency if people from a geo-tagging point of view, is located in Denmark, Norway or Sweden, while most other countries, should see the bar using Euros per default.

Best.

Rasmus