In C# .NET 2.0, what's an easy way to do a foreach in reverse?

Lets say I have a Dictionary object:

Dictionary myDictionary<int, SomeObject> = new Dictionary<string, SomeObject>();

Now I want to iterate through the dictionary in reverse order. I can't use a simple for loop because I don't know the keys of the dictionary. A foreach is easy:

foreach (SomeObject object in myDictionary.Values)
{
    // Do stuff to object
}

But how can I perform this in reverse?