Кнопка: получить текст из эдит чужого окна

HWND wnd, cwnd;
wnd = FindWindow(NULL, "имя окна");
cwnd = FindWindowEx(wnd, NULL, NULL, "имя кнопки");
SendMessage(cwnd, WM_LBUTTONDOWN, 0, 0);
SendMessage(cwnd, WM_LBUTTONUP, 0, 0);

char EDIT_TEXT[512]; // буфер
HANDLE temp = Form1->Handle;
SendMessage(temp, WM_GETTEXT, sizeof(EDIT_TEXT), (LPARAM)EDIT_TEXT); //получаем текст в буфер
ShowMessage(EDIT_TEXT);

SendMessage(Button2->Handle, BM_CLICK, 0, 0); // клик

SendMessage(cwnd, WM_LBUTTONDOWN, 0, 0);
SendMessage(cwnd, WM_LBUTTONUP, 0, 0);

SendMessage(cwnd, BM_CLICK, 0, 0);

//---------------------------------------------------------------------------
void wj_ClickKeyToWindow(int but, HWND Handle)
{
    if(IsWindow(Handle) == true, Handle != 0)
    {
        SendMessage(Handle, WM_KEYDOWN, but, NULL);
        SendMessage(Handle, WM_KEYUP, but, NULL);
    }
    else
    {
        // handle error
    }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button3Click(TObject *Sender)
{
    HANDLE tmp = Form1->Button1->Handle;
    wj_ClickKeyToWindow(VK_RETURN, tmp);
}
//---------------------------------------------------------------------------

wnd = FindWindow(NULL, L"KeyGen-XE2");
wnd = FindWindowEx(wnd, NULL, NULL, L"");
bwnd= FindWindowEx(wnd, NULL, NULL, L"Gen. Seriale");
 
SendMessage(bwnd, BM_CLICK, 0, 0);

SendMessage(e1wnd, WM_GETTEXT, sizeof(buff), (LPARAM)buff);
 
ShowMessage(buff);

wchar_t buff[500];
SendMessage(e1wnd, WM_GETTEXT, sizeof(buff), (LPARAM)buff);

char buff[500];
SendMessageA(e1wnd, WM_GETTEXT, sizeof(buff), (LPARAM)buff);