I am looking for anyone who may have been in the barrack in Bergen-Belsen in the Star Camp, and may have witnessed or took part in a secret Bar Mitzvah ceremony with Joachim Joseph (Yoya), conducted by Rabbi Simon Dasberg in April, 1944.

(A couple of details that might help someone remember)
The ceremony happened pre-dawn, with blankets on the windows. At one point the ceremony was interrupted with a knock on the door. It was the young boy