title: Caesar cipher in C++
body: <p>To start off, I'm four weeks into a C++ course and I don't even know loops yet, so please speak baby talk?</p>
  
  <p>Okay, so I'm supposed to read a twelve character string (plus NULL makes thirteen) from a file, and then shift the letters backwards three, and then print my results to screen and file.  I'm okay with everything except the shifting letters.  I don't want to write miles of code to take each character individually, subtract three, and re-assemble the string, but I'm not sure how to work with the whole string at once.  Can someone recommend a really simple method of doing this?</p>