Editing language files from a CMS. Help and advice please!!

[eluser]chiqui3d[/eluser]
Editing language files from a CMS.
I mean, how could I do to edit the files. "Php" variables of diferent languages​​?
Know her any library or class or function to make it.
Thank you!

[eluser]chiqui3d[/eluser]
This is file in codeigniter:

application/language/english/traduccion_lang.php

and

application/language/spanish/traduccion_lang.php

Can you help please?