How to initialize automatically an element into a Diagram (like SAB) ?

Hi,
I’m on the automation for initialize a Diagram (for now i’m in SA). For some of them, like the SAB, I will initialize an actor list or all of the actors of the project in these diagrams. I have tried to modified the content list of the diagram to insert my actor list but I did not succeed.
Does anyone know how to do it ?
Thanks