Thank you pavroo
Because the keyboard layout hasn't the ability to add as they do other distros under the main layout to add as many keyboards you like, I mistaken supposed that could not add at least another language.
I'm happy that it works fine and change with a shortcut key from English to Greek.
To inform other newbies its little tricky to choose the right layout if you have special characters as “€” and to see the results you have to reboot.
Many bravo to all who contribute and made the SparkyLinux specially the LXDE a lighting fast distro!