Similar to another just answered <How-to-plot-a-graph-for-one-set-of-data-against-two-y-axes-one-a-function-of-the-other> excepting was the second y-axis so could use yyaxis as start point (why there isn't its twin sister is anybody's guess...).
However, there is an example for "Multiple x- and y-axes" in the documentation for graphics that shows how to create the second overlaying axis; use that then the shown ideas above for the x-limits and x-tick values. Will have to use the venerable graphics handles to address the correct axis since there isn't a xxaxis for convenience (again, why not, TMW?).
