Open file with Esperanto characters `Ĝ` and `ĝ` in gVim

Question

I have an Autohotkey script to write Esperanto characters. It has the form

AppsKey & G::
    if GetKeyState("Shift", "P")
        send Ĝ

    else
    send ĝ
return

Notepad has no problem with opening it in a way that shows both Ĝ and ĝ. On the other hand Vim can't display them.

After reading https://stackoverflow.com/questions/5166652/how-to-view-utf-8-characters-in-vim-or-gvim I added to my _vimrc:

set enc=utf-8
set fileencoding=utf-8
set fileencodings=ucs-bom,utf8,prc
set guifont=Monaco:h11
set guifontwide=NSimsun:h12

Vim still doesn't display the character correctly. What do I have to do to get Vim to open the file properly?