Absolutely naïve question about line numbering and lisp code

[Armando Martins]

Hello!

I am trying to numer the lines of a text (not the buffer, although
this solution could work around). I google and I find files in lisp
code, say: num.el, setnu.el, line.el...
How can I make it work on a text file I have. Do I download (wherever)
and open it and click "evaluate lisp" and then it will work for all
the session?
I am using Windows Vista.
Thanks for your help

-- 
Com os melhores cumprimentos,

Armando Martins
Departamento de Linguística e Literaturas
Universidade de Évora, Largo dos Colegiais nº 2
7004-516 ÉVORA