Attach a dynamically-created register to a comms template

Our teams have comms templates set up for pre-event communication to instructors or venues that includes sending a register/list of delegates. Currently they must generate this register on the event, save it to the DMS then attach to the email in the ad hoc emailer. 

It would save time and effort (and potentially enable automated triggers to be used for these emails) if the comms template attachments could include a dynamically-created Register PDF.