Customize technical deliveries

[MicheleMir]

I need to customize the subject and the content of some technical deliveries, adding some informations to make these deliveries more readable for the operator that receives the communication.
For example one of the deliveries that I need to customize is "Notification of validations for the marketing campaign" (internal name:notifyValidation) but when I open the delivery the subject and the content are respectively: <%= dataSource.title %> and  <%= dataSource.message %> 

and the source page show the following code:

I would like to know if it's possible to modify those fields adding some variables like the localOrgUnit and what is the workflow or the activity that I need to modify to customize the content of these technical deliveries.