I have never done that but I would try something like this

IF GlobalEventSet("EquipItem")
AND ItemGetHandle(ITEM_MyItem, _Handle)
THEN CharacterEquipItemhandle(CHARACTER_MyNPC, _Handle);

Or,

PROC MyEquipItem((ITEM)_Item, (CHARACTER)_Char)
AND ItemGetHandle(_Item, _Handle)
THEN CharacterEquipItemhandle(_Char, _Handle);

Is the character a player or NPC ?
If NPC then, does it wear the same armor all the time or does it need to change the gear ?