Re: downcasting template class with paramaterised parent

I have a situation where I have a number of MFC derived
classes. For
example two classes are;

class MyEdit : public CEdit

and

class MyButton : public CButton

I want to derive MyEdit and MyButton from a common class
but to retain
the MFC inheritance.

Therefore I introduced a template class which has the
parent as a
parameter, e.g.;

template <class PARENT>
class MyControl : public PARENT

I now want to implement some common functionality in the
MyControl
class, e.g.;

template <class PARENT>
class MyControl : public PARENT
{
  ...
  Common()
  {
     // Do something
  }
  ...
}

I want to be able to call the Common method without
knowing the runtime
type of the object. I have a pointer to a CWnd which can
be downcast
to a MyButton or MyEdit.

How do I cast the CWnd pointer appropriately to call the
Common method?