stl template for ATL::CWindow

I'd like to be able to use stl strings to do functions like
GetWindowText(), SetWindowText(), etc... So, I thought it would be
handy to use a template that could be applied to ATL::CWindow derived
object. e.g.
    STLWnd<CEdit> m_edit;

Ideally, I'd like to be able to do something simple like:

#ifdef UNICODE
    #define TSTRING std::wstring
#else
    #define TSTRING std::string
#endif

template <class TBase>
class STLWnd :
    public TBase
{
public:
    STLWnd(void) :
        TBase()
    { };
    TSTRING GetWindowText()
    {
        ATLASSERT(::IsWindow(m_hWnd));
        int len = ::GetWindowTextLength(m_hWnd);
        std::auto_ptr<TCHAR> txt(new TCHAR[len + 1]);
        ::GetWindowText(m_hWnd, txt.get(), len + 1);
        return TSTRING(txt.get());
    };
    void SetWindowText(const TSTRING& str)
    {
        ::SetWindowText(m_hWnd, str.c_str());
    };
};

But, I'm having some trouble getting everything working.
The compiler complains that I don't have an = operator overloaded. But,
that way lies insanity as I end up re-implementing the entire
ATL::CWindow class. (Perhaps I'm just implementing it wrong...Is there
a right way to override the = operator?)

Can anybody offer any suggestions on getting this to work?

Thanks,
 PaulH