When a new user is added to AD they would get an internal mail address stored in the mail attribute username@yourdomain.com.  I want to copy that username to the pager attribute so that it looks like this username@google.yourdomain.com. 

The reason I need to do this is that we use the mail attribute on our internal mail server.  Google provides a AD sync called GADS which syncs AD and Google account information.  It helpfully will truncated the domain and add the Google one.  Google password sync GAPS is not quite so helpful.