Alors voici les liens vers les 2 librairies en questions :
http://libxls.sourceforge.net/
http://xlslib.sourceforge.net/
je vais de ce pas me renseigner sur ce que tu m'as dit ^^
EDIT :
alors libxls : GNU Library or Lesser General Public License (LGPL)
et xls lib :
xlsLib is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.