If would be very difficult to program anything in Notepad. You would also need a compiler. Microsoft has free versions of Visual Studio 2005 available (an Express edition). You can pick your programming language: Visual Basic, C# or C++. I recommend Visual Basic if you have no programming experience. You can download them at this link:
A Beta 2 version of Visual Studio 2008 is also available for free, but I recommend starting with the 2005 editions. Beta 2 has a few bugs. The 2008 versions will be available in the first quarter of 2008.