CGEventCreateKeyboardEvent and Sandboxes

I'm trying to do this piece of code to send keystrokes to a finder in a sandboxed application for Mac OS X:

    CGEventRef a = CGEventCreateKeyboardEvent(NULL, keycode, true);
    CGEventSetFlags(a, kCGEventFlagMaskControl);
    CGEventPost(kCGHIDEventTap, a);
    CFRelease(a);

      

        
        
        
      

    

It works in a non-sanboxed environment, but it doesn't work when it is isolated, also if I use this right:

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
     <dict>
       <key>com.apple.security.app-sandbox</key>
       <true/>
       <key>com.apple.security.temporary-exception.apple-events</key>
       <array>
       <string>com.apple.systemevents</string>
       </array>
     </dict>
  </plist>

      

        
        
        
      

    

I found someone suggested to use Apple Scripts instead, it works but it is very slow and not suitable for my needs.

Is there a chance?