What is the better solution for this problem

Let i have Three Class

1. ConfigurationA ---> SupperConf
2. ConfigurationB ---> SupperConf
3. CongigurationC ---> SupperConf

public interface SupperConf{}//empty

1. ConfigurationA{
   public void setProA(String proA){}
}

2. ConfigurationB{
   public void setProB(String proB){}
}

3. ConfigurationC{
   public void setProC(String proB){}
}


public final class ConfigurationManager{

   public static SupperConf getConfiguration(String confType){
      SupperConf conf = null;
      switch (confType)) {
        case "confA":
             configuration = new ConfigurationA();
        break;
        case "confB":
             configuration = new ConfigurationB();
        break;
        case "confC":
             configuration = new ConfigurationC();
        break;
       }
      return configuration;

    }

  }


public class app{
    public static void main(String agrs[]){
       ConfigurationA confA = ConfigurationManager.getConfiguration("confA");
   //Line 4 confA.setProA("proA");
    }

}

What changes do i have to do so that my code compile at line 4 confA.setProA("proA");

I Know i can achieve using typecast like below

ConfigurationA confA = (ConfigurationA)ConfigurationManager.getConfiguration("confA");

I want to achieve doing some change in design or any design pattern in java so that i could achieve.