Thank you everyone for your helpful advice!
However, I am still struggling.
I should have perhaps made my level of abilities more clear: when it comes to perl, I know absolutely nothing! The only thing I know is, that one is supposed stick the code into a text editor, stick the LaTeX commands around it, and then run it with perltex. Evidently, with code posted by Perlbotics, I am supposed to do something far more advanced?