Hello. To get the .Capx file just open your project on construct2 and then click file> Save as a single file.
This will generate your capx file, save this file on any folder of your dropbox account or any other domain, right click on it, select "get public Link" and then post the link on your comment.You can do the same with images.
You'll need 300 reputation points to post any link or images though, for more reputation go look here: http://www.scirra.com/badges