There are many different ways to give you're C++ program a Graphical User Interface (GUI). If you're writing just for windows, you can use C++.net to take advantage of windows forms or WPF. There are also many libraries like wxwidgets, qy, radC++, etc.
For C++ QT is a decent library and it is somewhat portable (it's distributed by Nokia now). There's a free pdf of a decent book(released by the author under Open Publication) at http://www.qtrac.eu/marksummerfield.html (the author's website).
He steps you through (and they are nice manageable steps) making a very small scale spreadsheet program.
There are lots of other options, like wxWidgets (I've never used but a lot of people like). Of course there's the whole gamut of Windows GUI tools -- Win32API (not the best place to start if you haven't done it before), MFC (which is C++ based), .NET (but you need managed C++ and this is a whole different animal).