Custom cpp mod in FillLoot->loot_templates

Im green with cpp, don’t bash me for being stupid if I’m. Need advice/tips/cpp.

I want to mod " loot->FillLoot(1, LootTemplates_Creature, this, true);" to take items from dead player’s inventory instead, filled in "charactersDB"item_instance (collumns I’m interested: owner_guid and "itemEntry’').

Now:

LootStore LootTemplates_Creature(“creature_loot_template”, “creature entry”, true);
LootStore LootTemplates_Disenchant(“disenchant_loot_template”, “item disenchant id”, true);
LootStore LootTemplates_Fishing(“fishing_loot_template”, “area id”, true);
LootStore LootTemplates_Gameobject(“gameobject_loot_template”, “gameobject entry”, true);
LootStore LootTemplates_Item(“item_loot_template”, “item entry”, true);
LootStore LootTemplates_Mail(“mail_loot_template”, “mail template id”, false);
LootStore LootTemplates_Milling(“milling_loot_template”, “item entry (herb)”, true);
LootStore LootTemplates_Pickpocketing(“pickpocketing_loot_template”, “creature pickpocket lootid”, true);
LootStore LootTemplates_Prospecting(“prospecting_loot_template”, “item entry (ore)”, true);
LootStore LootTemplates_Reference(“reference_loot_template”, “reference id”, false);
LootStore LootTemplates_Skinning(“skinning_loot_template”, “creature skinning id”, true);
LootStore LootTemplates_Spell(“spell_loot_template”, “spell id (random item creating)”, false);

Question:

Am I able to mod this to get, what I want? How to??? I see no VISIBLE FOR ME connections in code, where It’s possible to mod script<->creature_loot_template@world to instance_item@characters.

I will be grateful for anything. Where shall I search for what I need? Thank you.

BTW. First I thought about:

LootStore LootTemplates_Creature(“item_instance”, “owner_guid itemEntry”, true); or smth, but it’s not that simple I quess?