You can’t use HTML entity codes in CSS generated content - if you try you just end up with the CSS content spitting out the HTML reference code. But, you can use escaped UTF hex codes instead, and then everything works nicely. The solution to my problem was kindly found by the power of Google and provided by Alan Hogan.
You may need to find out what the UTF hex codes are for a character. I used UTF16 hexidecimal and it worked great.