The canonical domain for you application, ie www.natcheurope.com or login.natcheurope.com
Use a single C-name to point to the hostname you received from Natch, ie lb00.natchcloud.com. Make sure you don't have a duplicate entry as an A-record.
A naked domain is one without www, ie natcheurope.com.
Registrar support webforwarding?
Configure the webforward to redirect to your www-domain.
Registrar does not support webforwarding?
Consider moving to a registrar that supports webforwarding, like Combell.
Point your naked domain to 188.8.131.52 using an A-record. This is a free server by wwwizer that forwards the naked domain to the www-domain.