Delphi Form in C++Builder

I am using C++Builder 2006. I created one CPP Form and I added a Delphi Form 
to this project.The IDE generated the "*.hpp" which makes possible to
call 
the Delphi Form from the CPP Form including the auto-generated *.hpp file.
I can call the Delphi Form from this easily, just like I call another CPP 
form.
But I would like to call the CPP Form from the Delphi unit.
How could the C++Builder form be recognazable in the Delphi unit?
Is there any trick to "include" the CPP object to the Delphi unit?

Thanks!
Zoltan