For users of Shared cPanel hosting, the procedure for adding a CNAME entry is simple.
1. Sign into your cPanel account ( it will be something like http://your-domain.com/cpanel ).
2. Find the box headed 'Domains' and open 'Simple DNS Zone Editor'.
3. Select your domain from the drop-down box and in the section labeled 'Add a CNAME Record' add your mobile redirect (e.g. m.yourdomain.com). Even if you just add the 'm' cPanel will fill in the rest of the domain but this is ok.
4. In the second box add 'mobile.dudasite.com' then click 'Add CNAME Record' button and that's it.