I have figured it out.
Find /home/joomla/public_html/components/com_users/models/registration.php and add:
$emailBody = JText::sprintf( 'COM_USERS_EMAIL_ACTIVATE_WITH_ADMIN_ACTIVATION_BODY', $data['sitename'], $data['name'], $data['email'], $data['username'], $data['yourdatabasecolumn'], $data['siteurl'].'index.php?option=com_users&task=registration.activate&token='.$data['activation'] );
Find /home/joomla/public_html/language/en-GB/en-GB.com_users.ini and add:
COM_USERS_EMAIL_ACTIVATE_WITH_ADMIN_ACTIVATION_BODY="Hello administrator,\n\nA new user has registered at %s.\nThe user has verified his email, and requests that you approve his account.\nThis email contains their details:\n\n Name : %s \n Email: %s \n Username: %s \n Yourdatabasename : %s \nYou can activate the user by clicking on the link below:\n %s \n"
everything must be in the right order