VCB Reports with Service Now?

I'm integrating VCB with the third party Service Now. The Chargeback's Usage/Cost reports should be supplied to the tool. Service Now tool would like to know where does the Report's content (X,Y axis) are stored and in what format. I'm aware that these should reside in the Chargeback's database instance (MSQL) in this case).

Precise question is, how to extract these? What info from the DB to be given to Service Now while configuring?

Thanks!