A new eXe has been released today, version 0.21. One of the relatively new features of eXe is the ability to easily add a range of Creative Commons licenses to your published content.
To add a license switch to the Properties pane by clicking on the Properties tab above the authoring space. Select the license you wish to add by using the dropdown menu. Be sure to clickon the "Done" button before returning to the Authoring pane or your additions will not be saved.