Calling function in CLASS from DLL

[Shaii]

Hi,
I was able to run a simple function.

but my problem is different.
I need to run function Open from CLASS NCDCtrl.
I add the c++ code from the heder file as u can c I tried to
define it like:
extern "C" int _stdcall NCDCtrl::Open(char *);
but I got:
//error C2027: use of undefined type 'NCDCtrl'

here is the class:

class NCDCtrl : public CommCtrl
{
public:
NCDCtrl();
virtual ~NCDCtrl();

// overidden to open the port and also syncronies it's baud rate with the NCD.
BOOL Open(char *Com);
};

10x a million to u all !