Absolute path in Wordpress Network site

Question

This site is part of a Wordpress Network.

In the theme's CSS, I'd like to reference some font files using @font-face. The fonts live in the theme's directory.

If I use a path like this:

http://brinkley.doig.com.au/wp-content/themes/brinkley/myriadpro-boldcond.ttf

, the file is not found.

The true path is

http://www.doig.com.au/wp-content/themes/brinkley/myriadpro-boldcond.ttf

, but using this path in the CSS does not work (see this answer).

So, I have the problem of the true path not working in CSS, and the Wordpress network path not being found.