我已经获得外部程序toolbar的hwnd，用 SendMessage， PostMessage都是只能点击第一个按钮，怎么才能做到点击其它的按钮呢？

我的程序如下

          HWND3 = FindWindowEx(HWND2, 0, "TToolBar", vbNullString)

          If HWND3 > 0 Then
                      SendMessage HWND3, BM_CLICK, 0, 0
                      PostMessage HWND3, WM_LBUTTONDOWN, 0, 0    '对按钮按下鼠标左键
                      PostMessage HWND3, WM_LBUTTONUP, 0, 0
           End If