Heroku, GeoIP, Amazon Route 53

i was starting to setup 2-Region for my Heroku App, then create distribute the workload with Amazon Route 53 GeoDNS service.

Solution 1 fail

a = api.mydomain.com, Europe, myApp-EU.herokuapp.com
b = api.mydomain.com, US, myApp-US.herokuapp.com

a,b fail: since Heroku don't know "api.mydomain.com".

Solution 2 fail

a = api.mydomain.com, Europe, CNAME api-eu.mydomain.com
b =  api.mydomain.com, US, CNAME api-us.mydomain.com
c =  api-eu.mydomain.com, Europe, myApp-EU.herokuapp.com
d =  api-us.mydomain.com, US, myApp-US.herokuapp.com

c,d work since heroku know "api-eu.mydomain.com". a,b doesn't work since heroku don't know "api.mydomain.com"

At this point i would conclude that is not possibile with Herou?