CQWP and custom columns?

I've got the content query web part working to roll-up events from project calendars in our numerous project sub-sites.

HOWEVER, each calendar also has a column called "Project" where we keep track of the project name associated with an event.  Side note: Each project calendar was created so that when an event is created the default value of this column is the name of the Project.

Question:  In any case, I'd like to include this Project Name column in the CQWP roll-up.  Is there a way to do this?  So far I've only been able to access the values of the default calendar columns.

Thanks in advance.