Cakephp Asset.timestamp + CDN url

Hi there,
I’m currently using
Configure::write(‘Asset.timestamp’, ‘force’);
to add a timestamp to my asset-files. This works great, but now I want to serve my urls through a CDN using:

When I use fullbaseurl => true it uses the url without the subdomain. I tried various things (also trying to configure the imgbaseurl), but nothing seems to work.