prevent some users to create a project

Hi,

I would like to give access to the project manager to some users, giving them the possibility to see some poject created by others users but not giving them the possibility to create one projects?

I have tried with ProjectManager - Preferences - ACL in
index.php?menuaction=preferences.uiaclprefs.index&acl_app=projectmanager&owner=-23
with no success

Is it possible?

Thanks for your answers