Julie,
This is coming from the Projects Object. It is adding the CapEx and OpEx costs together. If you go into the report in view mode you can right-click over the KPI and it will show you were the KPI is coming from and how it was built.
!NEWCOLUMN[{Total Project Spend}=CapEx+OpEx][=Currency({$_},"#,###")][canSum]/

Cheers,
Ryan