This is a immortal command to allow immortals to clear a mortals
ONLY WORKS WITH VASSAGO'S QUESTCODE or ANYTHING SIMILAR TO IT

if you don't have the printf_to_char function get the one 
on this page

void do_questreset(CHAR_DATA *ch,char *argument)
{ CHAR_DATA *victim;
  char arg[MAX_INPUT_LENGTH];

  argument = one_argument(argument,arg);

  if (arg[0] == '\0')
  { 
    send_to_char("Syntax: questreset <player>\n\r",ch);
    return; 
  }                            

if ((victim = get_char_world(ch,arg)) == NULL)
  { 
    send_to_char("They aren't here.\n\r",ch);
    return; 
  }

  if (IS_NPC(victim))
  { send_to_char("Mobs dont quest.\n\r",ch);
    return; }

  if (IS_SET(victim->act,PLR_QUESTOR))
  REMOVE_BIT(victim->act,PLR_QUESTOR);
  victim->questgiver    = NULL;
  victim->countdown     = 0;
  victim->questmob      = 0;
  victim->questobj      = 0;
  victim->nextquest     = 0;                                         

 printf_to_char(victim,"%s has cleared your quest.\n\r",PERS(ch,victim));
  printf_to_char(ch,"You clear %s's quest.\n\r",victim->name);

  return;
}                  

Then interp.c put this

{ "questreset", do_questreset, POS_DEAD, IM, 1, LOG_NORMAL, 1 },

and in interp.h

DECLARE_DO_FUN( do_questreset