How do you make the Campaigns Table visible to ZOHO Reports

How do you make the Campaigns Table visible to ZOHO Reports

Hi 

I can see the normal tables from CRM in reports - Leads, Potentials and have used these to build some tables that give me conversion ratios by lead source, by month year to date etc.

However, what I would like to do is relate this information to the marketing campaigns so that I can see cost of lead, meeting, sale but can't see how you can access the Campaign table in Reports.

Any advice?

Nick