Mac Apple/Command key on linux (or even just "Command-key in emacs on linux")

[Livin Stephen]

I own and use a PowerBook G4.

Also, I'm an emacs user, and to save my pinky a lot of grief I use the
Command key () as the Ctrl key within emacs. This works fine when
using my local (powerbook) installation.

However, for work, I need to connect to linux servers using VNC. The
emacs installation I have running at work (being on linux) doesn't see/
recognise the command-key.

I'd like to know how the keyboard's Command Key can be mapped to Ctrl
on linux. Either using the linux OS or even just variables/options
within emacs-on-linux.