You can put the original interrupt handler back in place, you just need to stash away a function pointer to the old interrupt.

void (interrupt far *OldHandler)(); // Pointer to the original
                                    // error-handler routine.

void main(void)
{
   // Save original handler.
   OldHandler = _dos_getvect(INT24);    
   _dos_setvect(INT24, OldHandler);
}  

I would be very suprised if Borland C/C++ didn't have similiar functions.

HTH
Neil