Exporting classes with COM

I'm trying to write a COM object and I want to export some classes along with it.(as data types, not as COM objects)

I've defined a nuce class CComplex which holds a complex number (they're a bit like real numbers but more complex) and I've defined operators and casts for it.

I can export a data type using the typedef statement in the IDL file.

Code:

typedef [ uuid(29A70BDD-3427-4639-A2A7-691DDF51353F), helpstring ("Unsigned Long Integer") ] unsigned long ULI;

but If I want to do something like that for a complex number I get an error.

Code:

unsatisfied forward declaration

If I try to include the header files I need I get an

Code:

expecting a type specification near "include"

does anyone know how I can export my class?