Topic: Support and Troubleshooting / Customer domain name and CNAME

Hi!
I asked my provider to create a CNAME record as per example at http://ubik.com/tutorial/en/mobilizer/mobilizer_alternative_dns.html

They said that it was impossible to set CNAME record for the domain root, so they set it for the WWW record.
Does this mean that having own domain example.com I need to define a subdomain like subdomain.example.com and set CNAME record to point to it?
So this feature is not provided in order to use www.example.com both on PC and mobile device and display different sites accordingly?