This is currently logged as anEnhancement 26537.As an alternate solution, a Transaction Saved Search can be created.

1. Navigate toReports>Saved Searches>All Saved Searches>New
2. ClickTransaction
3. Search Title:EnterTitle
4. ClickCriteria
5. ClickStandard
   • SelectType
     1. Type:Selectany of
     2. SelectSales Order
     3. ClickSet
   • SelectStatus
     1. Status:Selectnone of
     2. SelectSales Order:Cancelled, Sales Order:Closed, Sales Order:Pending Approval
     3. ClickSet
   • SelectAmount Unbilled
     1. Amount Unbilled:Selectgreater than or equal to
     2. Value:Enter1
     3. ClickSet
   • SelectMain Line
     1. Main Line:SelectYes
     2. ClickSet
6. ClickResults
7. ClickColumns
   Note:For every required field use the drop-down menu to select it and once adjusted click Add if needed.
   • SelectDocument Number
   • SelectDate
   • SelectName
   • SelectAmount (Transaction Total)
   • SelectAmount Unbilled
   • SelectFormula (Numeric)
     1. Formula: Enter{amount}-{amountunbilled}
     2. Custom Label: EnterAmount Billed
   • SelectStatus
8. Show Totals:EnterCheckmark
9. ClickAvailable Filters
   • SelectDate
   • Show in Filter Region:EnterCheckmark
   • ClickAdd
10. ClickSave & Run