Since I'm unable to post my file here, and I was cross-posting this to my blog/lab notes site, you can get the non-proof-of-concept there: http://blog.mustmodify.com/pages/prince-page-numbering

I have HTML with embedded CSS that correctly replaces the content of the .language div based on the document's specified language, using:

html:lang(en) .language

As a proof-of-concept, that's great. I then tried to use it to change from "14 of 28" to "14 es 28" but that rule is ignored as though it were invalid. (and it may be, I can't find any documentation on how to use at-rules with selectors.)

I am using version 7.something

Please let me know whether it can be done this way, or whether I need to fudge it by dynamically generating this CSS.

Thanks, love your product.
jw

@page rules can't be mixed with element selectors, so I think this will require a snippet of JavaScript to enable the style that you want based on the language attribute.