http://www.wine-reviews.net/2015/11/how-to-install-gardencad-on-mac-with...

Trouble downloading the gCADPlus setup file?

If you want to install gCADPlus on a Mac and your Mac has virus checking software that will not allow the passage of the gCADPlus setup .exe file, try downloading a free Mac application called 'The Unarchiver' from the App Store. Then download the .7zip file from the download page of the gCADPlus web site. This 7zip file will bypass the virus checking software and The Unarchiver will unzip it ready to install under CrossOver. gCADPlus has been certified to run on a Mac under Crossover.

CrossOver - quick install