An application can retrieve a frame-control handle by using WinWindowFromID. The following code fragment retrieves the handle of a title-bar control:

HWND hwndTitleBar,hwndFrame;
hwndTitleBar = WinWindowFromID(hwndFrame, FID_TITLEBAR);

Given a frame-control handle, an application can retrieve its parent frame-window handle by using WinQueryWindow:

HWND hwndFrame,hwndTitleBar;
hwndFrame = WinQueryWindow(hwndTitleBar, QW_PARENT);

By using identifiers to identify frame controls, rather than using window classes, an application can create its own controls to replace the predefined controls.