How to use lock objects between 2 different applications

Hello,

I wonder how we can use lock objects between 2 different OOB applications.(Silverlight 5)
In the example below we can use lock objects to let only one thread to execute the code inside the lock object at a time.
This works fine within one application.

Now I wonder how we can use a lock object between 2 different applications. Is there some kind of Global system lock that
can be used?

I have put this code as illustration of what I try to find a solution for:

        object lockobject = new object();

        //Application 1
        void thread1()
        {
            Random rnd = new Random();
            while (true)
            {
                lock (lockobject)
                {
                    //Allow only 1 application at a time in this code area!
                }
                Thread.Sleep(rnd.Next(20, 2000));
            }
        }

        //Application 2
        void thread2()
        {
            Random rnd = new Random();
            while (true)
            {
                lock (lockobject)
                {
                    //Allow only 1 application at a time in this code area!
                }
                Thread.Sleep(rnd.Next(20, 2000));
            }
        }