> can you please help me with the following LISP code?
Looks fine.
> (define-derived-mode rct-mode special-mode "rct:main"
> "Major mode for remote connections
> \\{rct-main-mode-map}."
> (setq debug-on-error t)
Don't use `setq' in a major-mode since the change will affect
all buffers. Better use (set (make-local-variable 'debug-on-error) t).
> (use-local-map rct-mode-map)
> (run-hooks 'rct-mode-hook)
Don't do that, it's done by `define-derived-mode already.
> (main-menu))
This shouldn't be in the major-mode function, but in another function
(which will probably call the major-mode function).
> (switch-to-buffer rct-mode-buffer-name)
You should probably call pop-to-buffer here instead.
Stefan