DDE problem under Windows Vista

I hope I'm posting my problem under the correct group. Otherwise I'll be
grateful if you can show me what group to post in.

I have an application developed in TPascal7. The application
communicates with another application window using DDE, under the same
computer.

The application works perfectly on windows XP.

The problem I have occurs when the application is running unders Windows
Vista.

I am aware windows Vista is not supporting DDE comunication but i don't
understaed why the compatabiltity option not working.

Can someone have any idea how to run this kind of application under Windows
Vista?

Thanks in advance.