Disallow running a program as the wrong user

Using Windows 2008 Server, how can I allow a particular application to be run by one specific user, and prevent it from being run by any other user?

The scope is the local machine (the server) - I'm not concerned about a Windows domain. There is one, but I am only trying to apply restrictions for users logged into the physical server, or logged in via remote desktop.

From serverfault Joel

• Set the file permissions of the main program file to deny for everyone, and to full control only for the user you want to allow.

  Joel : Thanks. I realised this quickly after posting the question, and answered my own question. I'll accept this one.
  From c10k Consulting

• This was simpler than I thought it would be.

  It was just a matter of right-clicking the executable, Properties, Security tab. Removed execute permissions for all users. Added execute permission the specific user.

  That did the job. Didn't need to mess with group policy after all.

  From Joel