Sure, let's look at a .capx and see how we can fix what you have. Just save what you have as a Single File from your export options in C2, then upload that to something like, say, dropbox. Once you have that, use the insert hyperlink button on the forums posting options. It'll first ask for a name of the file (type whatever you want), then the url for the dropbox file (just right click and copy the link to the file in dropbox, then paste it into the url request).