header file in other dir as cpp file


We are working on a project with many cpp files.
To keep a good overview, we have arranged the cpp-files and the
accompaniying header files in seperate directories.
Now, in the IDE, when I want to open Source/Header file, with right-mouse
button or CTRL-F6, the IDE cannot find it and asks to create a new form,
unit or textfile. When I create a new file in another directory, it still
don't work. I know that MS VC6 does support the header-and cpp files in
different dirs, but how can we do this with BCB5?

Help Hans