When you have to put several entries into reftex-label-alist, just
put them after each other in a list, or create that many templates in
the customization buffer. Here is a lisp example which uses several of
the entries described above:
(setq reftex-label-alist
'(("axiom" ?a "ax:" "~\\ref{%s}" nil ("axiom" "ax.") -2)
("theorem" ?h "thr:" "~\\ref{%s}" t ("theorem" "theor." "th.") -3)
("\\quickeq{}" ?e nil nil 1 nil)
AMSTeX
("\\myfig[]{}{}{*}{}" ?f nil nil 3)
(detect-linguex ?x "ex:" "~\\ref{%s}" nil ("Example" "Ex."))))