Problem creating google apps cname

Hi, google apps request me to add a specific cname 12457895.mydomain.com So when i go to my Dns zone editor in WHM, i'm adding the record like this 53301 On hostname i add only 12457895 because the whm add automatically mydomain.com. when i save. In the empty blank box at the left i add google.com But when i check the propagation of the cname it not propagates and if i enter to the created cname it does not work. What is the error?