I guess now I understand You.
You should take a look at CALLBACK_PARAM_TARGETTILE,
Not tested. It should look like this
local combat = Combat()
combat:setParameter(COMBAT_PARAM_TYPE, COMBAT_ENERGYDAMAGE)
local area = {
{0, 0, 0, 0, 0, 0, 0},
{0, 0, 1, 1, 1, 0, 0},
{0, 0, 1, 1, 1, 0, 0},
{0...