template<class T>
class NCHandleConverter : public CXlUserConverterBase<T*, CString>
{
private:
    typedef T* ElemType;
    typedef CString XlNativeType;
public:
    virtual bool ConvertFromExcel(const XlNativeType& xlValue, ElemType& outerValue,
        const ParamsType& params) const
    {
        return HandleCache<T>::GetInstance()->HandleToPtr(xlValue, outerValue);
    }
    virtual bool ConvertToExcel(const ElemType& outerValue, XlNativeType &xlValue,
        const ParamsType& params) const
    {
        xlValue = HandleCache<T>::GetInstance()->CreateHandle(outerValue);
        return xlValue.GetLength() != 0;
    }
protected:
    virtual std::wstring GetTypeNameW(const ParamsType& params) const {
        return CXlLocalization::FormatW(XLMSG_TYPE_HANDLE_TO,
            params.GetStringParam(0).c_str());
    }
};
请大虾解释一下这个模板的意思，我是初学的，所以看不懂！！