Casting a class type as its known super class in Objective-C

Question

I have a parent class in which I would like to use a class variable with a known super class. Is there a way to tell the compiler what the super class is of a type?

My use case is much more complex using an external library (which is why I have to do such a strange thing. Here it is simplified:

@interface A
 +(void)MagicMethod;
@end


#import "A.h"
@interface B: A

@end


#import "A.h"
@interface C
{
    Class class_to_call
}

@implementation C
-(void) fun_method
{
   [class_to_call MagicMethod];  // I need some context here to say the base is class A!!!!
}
@end




#import "C.h"
@interface D: C
@end

@implementation D
-(id)init
{
   self = [super init];
   class_to_call = [B Class];
}

As you can see above, there is no way to give context to the class i'm using to call. Is there syntax to say that this "Class" variable holds a class with base type A?