mast0r!
You will find the answer by reading these two links: Google Geocoder Region Codes and IANA language subtags
In real usage a request would look something like this:
var geocoder = new google.maps.Geocoder();
geocoder.geocode({"address": your_address_string, "region": "NL"}, function(results, status){
if(status == google.maps.GeocoderStatus.OK){
//do what you want to do here
//to reach the full formatted address, use results[0].formatted_address
}
})