To fill your needs, you may use this article : http://ez.no/developer/articles/an_introduction_to_developing_ez_publish_extensions
Another tips :
1 - You may try to design your own module
2 - You may try some specific fetch function to fetch the information collection : http://ez.no/doc/ez_publish/technical_manual/4_0/reference/modules/content/fetch_functions/collected_info_collection