This is an Arma 3 Eden editor tutorial on how to make an Ai unit shoot at a specific object/target.
Copy & paste the following into the units init:
null = this spawn {_this dotarget t6; sleep 0.5; while {alive t6 and alive _this} do {sleep 4; gl action ["useweapon",vehicle _this,_this,0]; }};
• Change t6 to what ever you have called the target.
• Change gl to what ever you have called the game logic.
• Change 4 to alter the fire rate frequency.