activex控件是第三方吗?
如果是这样，我认为只有可能的方法是MoveWindow()和SetWindowPos()
否则，您可以将methode添加到activex控件并处理其中的大小调整逻辑，然后从客户端对话框中调用此methode.
但如果有许多客户使用此方法，则不是一个好的逻辑.

Is the activex control is 3rd party one??
if so i think only possible ways are MoveWindow() and SetWindowPos()
otherwise you can add methode to the activex control and handle resizing logic in it and invoke this methode from your client dialog.
but not a good logic if many clients use this.