How to prevent file copy, restricted by file size?

I am the administrator of about 800 PC under Windows XP/7 with Active Directory.

To limit the exchange of Divx, I'm looking for a software which prevents the copy of all file of more than 400 MB.

1. This program will be installed on every computer


2. This program doesn't affect the copy of small files


3. This program have not to prevent the opening of big files


4. This program must prevent the copy of local files, network shares, USB sticks...


5. Can display a message when a copy is blocked


6. This program should work on all profils of the computer


7. This program must work on the drag'n'drop and copy/paste of directories/files in Windows Explorer only


8. It's useless to prevent other way of copies (command line, copy software, save as...)

In fact, I think to supercopier of teracopy, with an extra option to forbid the transfert of big files.

The aim is to prevent the copy of big file of most users.