This is from Riouken on the BIS forums:
The Grad is artillery you need to create a fire mission and execute it. There is also a demo mission of this available.
// There is a arty logic ingame named arty1; _myBattery = arty1; // We need to make a arty fire mission template _heTemplate = ["IMMEDIATE", "HE", 0, 15]; // We need the postion of the target Above Sea Level. _targetPos = getPosASL target_1; // Here we check and make sure it is range then we exicute the fire mission. if ([_myBattery, _targetPos, _heTemplate select 1] call BIS_ARTY_F_PosInRange) then { [_myBattery, _targetPos, _heTemplate] call BIS_ARTY_F_ExecuteTemplateMission; hint "Firing... Sit back and wait, it will take about 60-90 seconds for the rounds to impact"; } else { hint "Target out of range!"; };