[boost] Passing parameters to container constructor

I'm in the process of writing my bdb container, and have used the container_gen template to tell boost which container to use. Now what I would like is to be able to pass some parameters to this container's constructor (e.g., the database's file name). After some time googling and reading the bgl book, I haven't been able to figure out how to achieve this. Any ideas ? Thanks in advance. Pierre.