This time i do not write to ask for help but just to share a workaround to a problem i had. It might be helpful in the future for noobs like myself.
I have LMCE installed on a laptop that has a wlan0 and an eth0. By default, LMCE considers that eth0 should be the external connection while wlan0 the internal one which is fine unless someone wants to have a good wireless router to send the signal all over the house.
So, my setup is the following: a modem-router from my provider, LMCE laptop connected to it via wlan0, eth0 connected to a second wireless router.
To make the switch initially i used the "swap interfaces" button on the networking section of the Web Admin but i was still getting eth0 as external. So i installed Wicd. From terminal i executed
sudo ifdown eth0
then i connected wlan0 to my provider's router. Afterwords, i went back into the terminal and excuted
sudo ifup eth0
and the connection to my second wireless router started automatically. Info about how the internal wireless router needs to be configured can be found at http://wiki.linuxmce.org/index.php/Internal_LAN_setup