first you need to place an artillery unit like Mortar.Then place game logic into the map. How? You place a new unit on map. then choose this :-
Side = Game Logic (not OPFOR or BLUFOR)
Class = Modules
Unit = Artillery
When you run the game, make sure youre the gunner. then press enter. you'll see an action list, one of them is artillery targetting. choose that. then a map will appear. in that map, you'll see some sort of reticule. adjust the bearing and angle of your mortar to bring the reticule over you're intended target. if you use Utes map, make sure you adjust your angle as vertical as possible until you can see the reticule. after you place the reticule over the target, you may release your deadly barrage. it will take quite a while before the round will hit. it's most likely that you'll fired all your rounds before the first round will land.
note : The artillery targetting are only working with mortar. i can't get it to work on other artillery pieces like M119, D30, MLRS and Grad. Is there anyone know how to make it work with other pieces beside mortar?