Have you tried using the same program that you open your downloaded cc with? A lot of those programs have the ability to create a zip file for you as well as open one. Try going to your file and right clicking on it and go to "add to archive". If it's not available, it may be nested under your utilities menu. For instance mine comes up first on the right click menu as "7-zip" and then there's an arrow next to it, I click on the arrow and the "add to archive" option shows along with several other options.
I hope I didn't confuse you with that, but let us know if you need more help. I'm looking forward to seeing what you have for us.

If you don't have a utility, here's a link to a free one:
7-ZipOnce you have it zipped go here to a tutorial on actually uploading it:
FAQ: How do I upload something on InSIMenator.net?