if you want to express " to make" or "to cause", you can use "使". The using way of "令" and "使" is same in your example. The "让" , you can use it too, it's same too in your example, but it have other meaning, such as "let" , it means "to order" , check this: 是他让我把椅子放在这儿的！ (He let me put the chair here!) In this case, it's strange to use "令" and "使". because they do not have a mood or a condition of "to order" . The "令", though this one word have a "to order" meaning, it just be the noun. if it be the verb, it means "to make", not "to order" or "to let". if you still be unclear to use these words, you can think about that: when you want to change something or someone to do something, you can use all; when you want to order or to let someone to do something , you can use "让" And, the "令" is used usually in writing.