How to expose a member's properties as the owner's own or inherit by receiving instance of parent's class

I'm receiving an object of class Foo from an API, say:

Foo instance = SomeoneElsesAPI.GetFooInstance(id);

I need use Foo, but also add properties to it of my own. The way I can think of doing this is:

class Bar{
    private Foo actual;
    public Bar(Foo actual)
    {
        this.actual = actual;
    }

    public string Prop1 { get {return actual.Prop1; } }
    public string Prop2 { get {return actual.Prop2; } }
    //...
    public string Prop23 { get {return actual.Prop23; } }

    public string MyOwnProperty1 { get { return ExternalSource.LoadInfo(actual.Id) } }
}

It feels dirty!

Is there anyone out there that knows how to cleanly expose members of a member as a class's own, or maybe how to extend Foo and have Bar's constructor take an instance of Foo?