\_ I had already done this, and on your advice I have done so again.  All I get
\_ from C-h a regexp is a list that indicates EMACS has a built-in macro to
\_ perform an interactive 'replace-regexp-with-string' but no interactive
\_ facility that amounts to 'replace-regexp1-with-regexp2-refering-to-regexp1.'

EerrrHh?  I get a list including query-replace-regexp, which is what I
think you want.  I'm running FSF emacs; if you're running Xemacs,
YMMV.

David