Is there an easy possibility to make a copy constructor?

[WaldeMar1321]

Greatings, I realy like your project as a now and then C++ programmer. I have an issue I listed in a "pseudo code" below:
A.h
class A
{
private:
Document sheet;
public:
A();
~A();
}
A.cpp
....
A::A() : sheet()
{
//do stuff
};
void click_button_and_open_file()
{
//we open some exsel file here
//and here I want to setup my sheet (Document instance with an open file) like:
QXls::Document temp(fileName);
sheet = temp; //or something like that.
}