Make implementation link between different languages

Hello.

Please help me with understanding how to implement PSI "implementation link" between interface in one language and implementation in another.

I'm developing ICE framework support plugin. The framework have own language (Slice) for own files. The Slice scripts are translated into java code. To hide generated code from user, I'd like to have navigation from Slice file to Java implementation.
For example:
Slice file:

{code}
// **********************************************************************
//
// Copyright (c) 2003-2011 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

#ifndef HELLO_ICE
#define HELLO_ICE

module Demo
{

interface Hello
{
    idempotent void sayHello(int delay);
    void shutdown();
};

};

#endif
{code}

ICE generates a java files which could be used like
{code}

// **********************************************************************
//
// Copyright (c) 2003-2011 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

import Demo.*;

public class HelloI extends _HelloDisp
{
    public void
    sayHello(int delay, Ice.Current current)
    {
        if(delay > 0)
        {
            try
            {
                Thread.currentThread().sleep(delay);
            }
            catch(InterruptedException ex1)
            {
            }
        }
        System.out.println("Hello World!");
    }

    public void
    shutdown(Ice.Current current)
    {
        System.out.println("Shutting down...");
        current.adapter.getCommunicator().shutdown();
    }
}