try like that.
local combat1 = createCombatObject()
setCombatParam(combat1, COMBAT_PARAM_TYPE, COMBAT_ICEDAMAGE)
setCombatParam(combat1, COMBAT_PARAM_BLOCKARMOR, FALSE)
setCombatParam(combat1, COMBAT_PARAM_EFFECT, CONST_ME_ICE_AREA)
setCombatParam(combat1, COMBAT_PARAM_DISTANCEEFFECT...