May be a simple action but I can't managed to hit any locked object. Character will only attack enemies.

But be careful with that option. In NWN2 there is a good chance that items in a chest are destroyed if you bash it open.

Just hold right click on the object (chest, door etc...) and press "Attack" button.

Keep in mind like ludgerarnold said, any time you bash a chest you might destroy an item in it, so it's always better to lockpick it.

cheers, got it