You could limit access to the folders on the server using AD Groups / UserNames, so only allow those named users you want to have access to the .qvw file to actually get into the folder. Using this method they won't be able to even see the file in Access Point.
We use it regularly to limit access to all types of users and maintain a neat and tidy Access Point for end users...they do get confused ever so easily!
Alternatively add Section Access to the application and don't include them within the approved users.
Hope that helps,
Matt - Visual Analytics Ltd
I have a tutorial from Rakesh.
Which helps you on Server administration.
In it its clearly mentioned how to acheive this.
Hope it helps