This is a script that installs lxpanel transalation and makes some links from es_AR translations existing in the original Slitaz 4.0 installation. I expect to complete it with other translations in this forum. You must download the script at: http://vmlinuz.16mb.com/files/slitaz40/scripts/update_es_lang_0_1.sh and execute as 'root' (after doing chmod +x to the file).
If you prefer just the lxpanel.mo file: http://vmlinuz.16mb.com/files/slitaz40/patches/lxpanel.mo