Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 4 monsters During either player's turn, when another card or effect is activated that targets exactly 1 card on the field (and no other cards): You can detach 1 Xyz Material from this card, then target another card on the field that would be an appropriate target for that card/effect; that card/effect now targets the new target.
--暗遷士 カンゴルゴーム
--Cairngorgon, Antiluminescent Knight
local s,id=GetID()
function s.initial_effect(c)
	--xyz summon
	Xyz.AddProcedure(c,nil,4,2)
	c:EnableReviveLimit()
	--replace
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_QUICK_O)
	e1:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e1:SetCode(EVENT_CHAINING)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCondition(s.condition)
	e1:SetCost(Cost.DetachFromSelf(1))
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	if e==re or not re:IsHasProperty(EFFECT_FLAG_CARD_TARGET) then return false end
	local g=Duel.GetChainInfo(ev,CHAININFO_TARGET_CARDS)
	if not g or #g~=1 then return false end
	local tc=g:GetFirst()
	e:SetLabelObject(tc)
	return tc:IsOnField()
end
function s.filter(c,ct)
	return Duel.CheckChainTarget(ct,c)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	local ct=ev
	local label=Duel.GetFlagEffectLabel(0,id)
	if label then
		if ev==(label>>16) then ct=(label&0xffff) end
	end
	if chkc then return chkc:IsOnField() and s.filter(chkc,ct) end
	if chk==0 then return Duel.IsExistingTarget(s.filter,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,1,e:GetLabelObject(),ct) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TARGET)
	Duel.SelectTarget(tp,s.filter,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,1,1,e:GetLabelObject(),ct)
	local val=ct+(ev+1<<16)
	if label then
		Duel.SetFlagEffectLabel(0,21501505,val)
	else
		Duel.RegisterFlagEffect(0,21501505,RESET_CHAIN,0,1,val)
	end
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local tc=Duel.GetFirstTarget()
	if tc and tc:IsRelateToEffect(e) then
		Duel.ChangeTargetCard(ev,Group.FromCards(tc))
	end
end