Is there a way where I can do something using C++, and which languages would you recommend I learn for being able to interface embedded hardware with windows or other operating systems, where I can control the programs in the OS using the hardware I build
Yes, you can program in C++ but some knowledge of Windows environment is necessary (WIN32, MFC, COM), here is explained how to do an MFC application to automate Power Point using MFC (Microsoft Foundation Classes):
http://support.microsoft.com/kb/237554/en-us?fr=1
If you learn how to open a serial port on Windows and read/write data, you can easily create a communication link between Arduino and a client application on the PC.
If you already know C++ and object oriented programming, I suggest you to learn C# language for programming Windows applications.