This function copies a rectangle from prclSrc to prclDst.

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

HAB       hab;      /*  Anchor-block handle. */
PRECTL    prclDst;  /*  Destination rectangle. */
PRECTL    prclSrc;  /*  Source rectangle. */
BOOL      rc;       /*  Success indicator. */

rc = WinCopyRect(hab, prclDst, prclSrc);