Create class with string name

I have an abstract class and derived classes.
I create new derived class with:
MyAbstractClass class1=new DerivedClass(parameter1, parameter2);
It works well but I have to create them with the string name of the derived class.
Something like this :
MyAbstractClass Class1=new StringName(parameter1, parameter2);
How can I do ?
thanks !

What do you mean by string name? can you make some examples?

Crosspost on the forum, here’s the answer.

Please, when you cross post, at least include the links to your crossposts.