L2 net help

Hi i recently managed to setup a l2 net in a sever that i am playing .The thing is that the server has custom farm zone with custom mobs that looks like players and l2 net does not read them as mobs with a result of not attacking them. If i switch  the targeting option to both players and npcs will attack them but it will attack also other players who comes near me .So is there any way to attack them without risking hitting someone else?