gnu screen key binding question - bind a key to: stuff a command + unbind the key binding?

[Zenaan Harkness <zen@freedbms.net>]

Does anyone know off-hand how to bind a key in .screenrc, eg

  bindkey -k k8 screen

so that the bound key causes some keystrokes to go into the terminal
to run that command, as well as "at the same time" (probably just
prior, or after) to unbind that same keybinding from the 'current'
screen session?
So I guess this is almost a screen script.

The most I've done so far is eg:
bindkey -k k8 screen
to open a new screen.

Also, of note, does anyone know what the difference is between bind
and bindkey. I've tried reading the manpage on these two things a
couple times now, and I'm not properly grokking the difference for
some reason...

TIA
Zenaan