[Prizrak.ya]

подскажите, пожалуйста, как определить handle главного окна процесса по его pid или имени файла

[NumLock]

BOOL EnumThreadWindows(
DWORD dwThreadId, // thread identifier
WNDENUMPROC lpfn, // pointer to callback function
LPARAM lParam // application-defined value
);

Parameters

dwThreadId

Identifies the thread whose windows are to be enumerated.

lpfn

Points to an application-defined callback function. For more information about the callback function, see the EnumThreadWndProc callback function.

lParam

Specifies a 32-bit, application-defined value to be passed to the callback function.

Return Values

If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero.

--

BOOL CALLBACK EnumThreadWndProc(
HWND hwnd, // handle to window
LPARAM lParam // application-defined value
);

Parameters

hwnd

Identifies a window associated with the thread specified in the EnumThreadWindows function.

lParam

Specifies the application-defined value given in the EnumThreadWindows function.

Return Values

To continue enumeration, the callback function must return TRUE; to stop enumeration, it must return FALSE.

Remarks

The callback function can perform any desired task.
An application must register this callback function by passing its address to the EnumThreadWindows function. EnumThreadWndProc is a placeholder for the application-defined function name.