Assign A Type To An Object At Runtime In .net Or C#?

I have an object, o, and a type, T. I'd like to use reflection to change object o to type T at runtime without instantiating it.The equivalent at compile time would be:

Dim p as Point = Nothing I know how to use Activator.CreateInstance to create an instance at run time that is equivalent to: Dim p as New Point()

But i don't want to do this. I have no knowledge of the type's constructor parameters and some types don't have a parameterless constructor. eg. Font. So, to sum up, I'd like a way of performing the equivalent of: Dim o as T = Nothing

In case you're wondering why I'm doing this, it's because I'm using a PropertyGrid on a form to edit types. If this is the first time for editing, say, a Font, then passing an uninitialised Font to the PropertyGrid makes the grid display the default values.

I tried 'o = GetUninitializedObject(T)', but the PropertyGrid either wants a properly initialised object or an object, with a defined type, set to nothing.

I've actually solved my particular problem here: how-to-use-the-property-grid-in-a-form-to-edit-any-type

, but i'd still be interested to know how to assign a type at run-time without the use of a wrapper class (which I was lucky enough to be using).