I have uploaded the spreadsheets that I use to calculate the CONCACAF club and league coefficients to the public FTP site of my company, Soccermetrics Research & Consulting. I am using this site to host my publicly-available software projects, and while the the spreadsheets aren't software per se, they do represent one of my early projects when I was getting started in statistical analysis in soccer and they do attract interest from fans and other analysts. I will place future revisions of the coefficients on that site.
The site is anonymous FTP, so when you follow the link, you will have to enter email@example.com in the username field followed by any text in the password field. If you use a FTP client, the server address is the aforementioned link and username/password combination.
Just a caveat that these coefficients are unofficial, and are not necessarily the same as those that CONCACAF use internally to rank Central American leagues. If you would like more information on how the coefficients are developed, please consult this post.