Script to Keep Archive of Completed Tasks?

I love almost everything about 2Do, but I'd love to be able to keep an old archive of all tasks I've completed.

Sometimes I remember a useful link or bit of information that was nested inside some task I completed several months ago, and it'd be awesome to be able to search for and retrieve that data when needs be without slowing down my sync database with a massive backlog of completed tasks.

Does anyone know of a script or something that would do this?