You actually compose your questions within PowerPoint using a special CPS toolbar. After engaging your question with the clickers, you'll see a screen like the one shown here.
This is a nice upgrade from the typical CPS screen which is pretty basic, even boring looking.
You can download the CPS for PowerPoint software from the eInstruction download page: http://einstruction.com/Downloads/index.cfm
And remember, you can only use this version of the software in conjunction with PowerPoint. If you want to use the regular CPS software you'll need to have it installed on your computer also, it's not replaced by the PPT version (so don't uninstall it like I did!)