[AUCTeX] reftex-label-alist for ctable package

[Michael Bach]

Hello AUCTeX users and developers,

I am trying to add local support for the ctable package (which I
really like btw) to the reftex label-reference mechanism.

The ctable macro has the following exemplary structure:

\ctable[
  pos = htbp,
  cap = shortcap,
  caption = longcap,
  label = tab:me,
  ]{lll}{
  \tnote{Who is that guy?}
  }{
\FL
Me & Myself & I
\ML
how & are & you? \NN
I\tnote& am & fine
\LL
}

I am using the following definition for the reftex-label-alist after
reading the built-in help:
(setq reftex-label-alist '(("\\ctable[*]{}{}{}" ?t "tab:" "\\ref{%s}"
1 ("table" "Tabelle"))))

What works: The *RefTeX Select* buffer appears with correct table type
labels and correctly shows the context for each label - context being
the optional argument [] for ctable macro.

The problem is that it also sets the %s string to the context, i.e. it
inserts all pos = ..., cap = ..., etc. inside \ref{...}. Now I am
thinking this has to do with the parsing for a \label{} macro which
fails.

My actual question(s): Are my thoughts correct? How would I change the
\label{...} to label = ... matching?

I have only found one related posting [1] to the comp.emacs list. I am
also writing this up since this could then be added to the
reftex-label-alist-builtin to support the ctable package.

Thanks in advance and Best Regards,
Michael Bach

[1] 
http://compgroups.net/comp.emacs/reftex-label-alist-and-the-ctable-environment/22334