Gavin,The person who wrote the program frequents the DIY Audio forum in the speaker subforum.
http://www.diyaudio.com/forums/forumdisplay.php?forumid=6
I have asked him (Svante) questions in the past and found he is very helpful. I recommend that you address any specific questions in that forum, if you go directly to the source you will probably get the best answers.
Martin