He does not want to talk about the past. He wants only to concentrate on the present and on the future.
Remember that the past is represented in the present. How-he- was will be mirrored by how-he-is. Remember, in his mind, you are in an dramatization (a re-enactment) of one of his relationships just by being in the room. One up – one down, doctor-patient, parent-infant, authority-underling, therapist-client, teacher-student, bully-victim, etc. There are many possibilities. You are only a prop in his play. One of the things he can do in psychotherapy is work out with you that which he needed to work out with the person(s) you represent (whoever that is).
While he concentrates on the present and future, you concentrate on the transference, the relationship between the two of you in the present. He may think of the present as today, out there. When you think of the present, think of this moment, in here.
Direct your interventions to inviting his awareness of his process in the moment.
When he is not focused on his relationship with you or someone else, direct him to be aware of his relationship with himself. “What is your response to what you just said?”
Something I’d be tempted to say is, “Okay, we won’t talk about the past but before we get started on the present, could you tell me what it is specifically in the past that you don’t want to talk about? Just so I’ll know to avoid it.”
Facilitate work in metaphors, dreams, imagery, art, stories, even movies. You do not have to know the specific content and he does not have to be aware that the “past” will show up whether he wants it to or not.
Sure. Use them just like dreams. Tell the story. Tell the story as if it is happening now. Have him speak for each of the characters and major objects. Have the characters and objects communicate with each other. Invite multiple or more satisfying endings. His psyche will do the rest of the work.