Quintero,

 Thank you. I see your way and I had done similar with it. Please see the follows:
  hr = srpVsUIShell->CreateToolWindow(
                                   dwCreateToolFlags,
                                   0,
                                   srpCodeWin,
                                   CLSID_NULL,
                                   guidToolWindow,
                                   GUID_NULL,
                                   NULL,
                                   csCaption.GetBuffer(),
                                   NULL,
                                   &srpWindowFrame);
  Sorry, maybe I don't say clearly.  I have place codewindow in tool window and hook a language service. However, a problem confuses me.
  When the tool window is float, please see the right-bottom of the window and you can see a triangle. If the mouse hovers on the triange, we can resize the tool window. However, if set the tool window to dockable and drag it to bottom aligned with output tool window, I also see the triangle, and if resize the window, UI won't redraw. Forthermore, I try the case on output tool window but I found the triangle disappear when ouput window is set to dockable. So I want to know how to "disable" the triangle?

Thanks
Hercules