Is it possible to type c++ or something into a text document and save it as .exe excutable so you can double click on it and it will open up a blender excutable or another excutable/program?
nope not possible, for it to work as an .exe you would have to compile it in a c++ or whatever programming language compiller
How about using a shortcut 
Or you could write a *.bat file in notepad. But to get an exe, you need to code and compile it.