I would like to add a hairline space &8202; around em-dash in the replace function.

prince-text-replace: "—" " — "

This will add a full space on either side of the em-dash.

But I want a hairline space or possibly a thin space surrounding the em-dash/.
How can I do that?

To answer my own question: I googled em-dash and found
http://en.wikipedia.org/wiki/Space_%28punctuation%29

Normal space versus hair space
(as rendered by your browser) Normal space left right
Normal space with em dash left — right
Thin space with em dash left — right
Hair space with em dash left — right
No space with em dash left—right

So hopefully this works

prince-text-replace: "—" "— "

Jim Albright
Wycliffe Bible Translators