Already solved it
local combat = createCombatObject()
setCombatParam(combat, COMBAT_PARAM_BLOCKARMOR, 1)
setCombatParam(combat, COMBAT_PARAM_TYPE, COMBAT_PHYSICALDAMAGE)
setCombatParam(combat, COMBAT_PARAM_DISTANCEEFFECT, CONST_ANI_PIERCINGBOLT)
function onGetFormulaValues(cid, level, skill...