DosSetVec

#define INCL_DOSMISC

USHORT  rc = DosSetVec(VecNum, Routine, PrevAddress);

USHORT           VecNum;             /* Function request code */
PFN              Routine;            /* Handler routine */
PFN              PrevAddress;        /* Previous handler address
                                         (returned) */

USHORT                   rc;         /* return code */