I have tried with google translation api, for now I think is acceptable solution, but I have a problem. These are my steps:
1) Copy a locale and cloned english to Italian
2) Downloaded Italian xml
3) Openend Italian xml and I get portion xml nodes within of <item key="/usr/local/cpanel/base/frontend/x3/lang/it.legacy_duplicate.english">
4) I translated 2802 nodes (phrases) with google api, I passed every string with htmlentities(utf8_decode( "....." )) and writed on file.
5) I opened this file formed of 2802 nodes translated and replaced with original file
6) I uploaded the new italian xml file but Cpanel return this error: "The file does not contain well formed XML according to... "