How can I add my font to the font menu? ​

If you have set w32-use-w32-font-dialog to nil, you can add fonts to the font menu by changing w32-fixed-font-alist. For example:

emacs-lisp
(setq w32-fixed-font-alist
   (append w32-fixed-font-alist
      '(("Monotype.com"
         ("8" "-*-Monotype.com-normal-r-*-*-11-*-*-*-c-iso8859-1")
         ("9" "-*-Monotype.com-normal-r-*-*-12-*-*-*-c-iso8859-1")
         ("10" "-*-Monotype.com-normal-r-*-*-13-*-*-*-c-iso8859-1")
         ("11" "-*-Monotype.com-normal-r-*-*-15-*-*-*-c-iso8859-1")))))