Use realname (not username) in email notifications

Hi folks.

I've searched through the issues without finding a solution to my problem. Apologies in advance if I've missed the answer somewhere.

I've got the Realname module installed which is working well in most cases, but I can't seem to figure out how to configure email notifications (eg. registration) to replace the username with the 'realname'.

As I understand it the email notifications use a simple string from the user object, whereas the realname is 'themed' html. Is it possible to get email notifications to use the realname?

Am I going to have to write some code to do this? Where should I start?

Any help would be very much appreciated.