This function obtains any current clipboard owner window.

#define INCL_WINCLIPBOARD /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HAB     hab;               /*  Anchor-block handle. */
HWND    hwndClipbrdOwner;  /*  Window handle of the current clipboard owner. */

hwndClipbrdOwner = WinQueryClipbrdOwner(hab);