Как, зная HWND кнопки на TaskBar, найти HWND соответствующего окна приложения?

HWND GetMainWindow(HWND hwnd) {
    HWND result=NULL;
    HWND tmp=GetParent(hwnd);
    while (IsWindow(tmp)) {
        result = tmp;
        tmp = GetParent(result);
    };
    return result;
}

int iSize = 200;
char *szText = new char[iSize];
DWORD dwProcessID;
char **lp;

HWND hWndTaskbar = FindWindow("Shell_TrayWnd", NULL);
hWndTaskbar = FindWindowEx(hWndTaskbar, NULL, "ReBarWindow32", NULL);
hWndTaskbar = FindWindowEx(hWndTaskbar, NULL, "MSTaskSwWClass", NULL);
hWndTaskbar = FindWindowEx(hWndTaskbar, NULL, "ToolbarWindow32", NULL);

GetWindowThreadProcessId(hWndTaskbar, &dwProcessID);
HANDLE hProcess = OpenProcess(PROCESS_VM_OPERATION | PROCESS_VM_READ | PROCESS_VM_WRITE, 0, dwProcessID);

lp = (LPSTR*)VirtualAllocEx(hProcess, NULL, iSize, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);

int max = SendMessage(hWndTaskbar, TB_BUTTONCOUNT, 0, 0);

for(int i = 0; i < max; i++)
{
            if (SendMessage(hWndTaskbar, TB_ISBUTTONHIDDEN, i, 0))  continue;

            memset(szText, 0, iSize);
            SendMessage(hWndTaskbar, TB_GETBUTTONTEXT, i, (LPARAM)lp);
            ReadProcessMemory(hProcess, (LPVOID)lp, szText, iSize, 0);

            HWND hWndButton = FindWindow(NULL, szText);
            HWND hWndOwner = GetWindow(hWndButton, GW_OWNER);
            if(hWndOwner)  hWndButton = hWndOwner;
}

delete[] szText;
VirtualFreeEx(hProcess, lp, 0, MEM_RELEASE);
CloseHandle(hProcess);
}