How to configure a separate folder for CGI scripts with Cheyenne?

Question

I have a web application contained in the following structure:

/app-root
+-- /html      ; root files
    /cgi-bin   ; cgi scripts
    /app       ; application files
    /cheyenne  ; Cheyenne binary and config

My initial config is:

default [
    root-dir %../html
]

How do I configure Cheyenne so that when I go to http://site/cgi-bin/foo.cgi it will look for foo in app-root/cgi-bin and not app-root/html/cgi-bin?