Have you looked at Maximus's ERS?

They have a module that sounds like it does what you are trying to do.
We use ERS, but not the activity reporting module that plugs into it.

======================================================================
 Instructions on how to use the RESADM-L Mailing List, including
 subscription information and a web-searchable archive, are available
 via our web site at http://www.healthresearch.org (click on the
 "LISTSERV" link in the upper right corner)

 A link directly to helpful tips:  http://tinyurl.com/resadm-l-help
======================================================================