Dongan, thanks for your help.
I created the variable as txt_description_footer, gave some value ( just text ), inserted on Description field ( admin ), then when I go to that product ( customer area ) , it shows me the raw code ( {$lng.txt_description_footer}.
Should I add any HTML tag before that ?
Sorry, it must be something in front of my nose, but I can't see it
Thanks !
aldo