Egg, attached are two files in a ZIP: Vertical Nav.zip

Open CSS3 - Vertical Dropdown Menu II.xar > !navbar layer and use Ctrl+Shift+Alt+A to attach Vertical nav.htm to the Red Box.
Hide !navbar.
Run.

CSS3 - Vertical Dropdown Menu II.xar

Normally Vertical nav.htm to would not be part of the Xara file but this was the easier way to demonstrate.
One would FTP it to a folder and edit separate from Xara.
Note the file does not need HTML tags.

Acorn