How to cast to child class

I am quiet new to UE4, the situation is I have created a new class called AMycharacter in c++ which is inherited by ACharacter, then I compiled and created a new blueprint called AMycharacter_BP in launcher which is inherited by AMycharacter, here it comes the problem, I have spawned a AMycharacter in c++ code, is there any way to cast it to its child class AMyCharacter_BP in blueprint?

First off, it is “inherits” the way you use it.

And no, not really. You have to spawn the class that you want. You can spawn the BP actor from c++ and then it should work