seems to be difficult to develop but since I need to migrate also a 1.9 resource module that was emulate a kind of repository, I realise that It would be usefull to develop it for legacy course files also. Teachers will then take good habits with the new moodle repository system.
If some one has deep developping informations on repository and file process in Moodle 2.x it would be possible for me to develop that kind of tool