Prefix key to send next keypress to terminal (reverse escaping)

[R. Diez]

Hallo all:

I am using multi-term to open shells inside emacs, and I have noticed that the 
terminal escape character is C-c (see term-set-escape-char).

However, I want the escape character to work the other way around. I mean, all 
normal emacs key bindings should remain active, and, if I want to pass a 
particular keypress combination to the child process in the terminal, I would 
like to press a prefix key first (like C-c, or maybe something else), and then 
anything that I press afterwards (perhaps including M-x) goes to the terminal, 
bypassing the normal emacs key bindings.

Is there a way I can achieve this? I am not a Lisp or emacs guru, I haven't 
found any hints on this subject.

Please copy me on any replies, as I am not subscribed to this list.

Many thanks in advance,
    rdiez