Windows Phone 7 - OrderedDictionary / alternatives

I'm completely new to C#, so I'm about to make a horrible attempt at my own version of an OrderedDictionary unless someone can suggest an alternative.

I need to be able to access my elements by array index, retaining the order they were added, and I also will be frequently updating individual elements using their key.

Is there a collection that allows this on the phone?
If I keep a List and Dictionary will they both be pointing to the same item or is there some kind of pointer thing I have to do?:
```
Item i = new Item();
list.Add(i);
dict.Add("key", i);
```

Solution

Using a List and a Dictionary is probably a good option actually. The "pointer thing" that you're talking about happens by default for Objects in .NET (any class and/or structure). All objects in .NET are passed around by reference.

So, if you use:

Item i = new Item();
list.Add(i);
dict.Add("key",i);
Console.WriteLine(list.Last() == dict["key"]);

Your output will be "true".

Best of luck!