title: How to prevent access to local file system
body: <p>I have a situation in which my (C#) application can load external DLLs (not written by me) and execute code from those libraries. The libraries can be C# or CPP.</p>
  
  <p>I need to make sure this external code won't access any files in my local file system (read and write) except from a specific folder.</p>
  
  <p>How can i do that?</p>