It cannot be moved, but it can be rebuilt as you showed:

• System commands/menus can be moved, but commands/menus created with NS can be "locked in place" when created, after which they cannot be moved.
• Create "Add to" in "More options"

menu(mode="multiple" title=title.more_options image=icon.more_options)
{
 menu(title='Aggiungi a' image=\uE001) { }
}

or

menu(mode="multiple" title=title.more_options image=icon.more_options) { }
menu(mode="multiple" title='Aggiungi a' image=\uE001 menu=title.more_options) 

• move the items in sub menu 2nd level

modify(find='Aggiungi' menu=title.more_options+'/Aggiungi a')

or

modify(find='Aggiungi' menu='@title.more_options/Aggiungi a')

Please, be patient. You know I'm a little clumsy. I don't know where to intervene since there is no MoreOption.nss file.
I had made this menu:

menu(title='Aggiungi a' image=\uE0C9)
{
modify(find='Aggiungi ad Accesso rapido' menu='Aggiungi a')
modify(find='Aggiungi al menu Start (Open-Shell)' menu='Aggiungi a')
modify(find='Aggiungi a Start' menu='Aggiungi a')
modify(find='Aggiungi alla barra delle applicazioni' image=\uE17B menu='Aggiungi a')
}

I called it "aggiungi.nss" and imported, and it works fine.
Now where can I transfer its content so I can see the menu inside other options?

Thanks a lot. It works :-)

PS Had you have a look to "Donation" post in Q&A section?