Using P512000 from WO Screen for WO Cost

Trying to use P512000 "Job Status Inquiry" from P48201 row exit to show WO cost. Unable to pass WO number to Subledger - SBL using form interconnect. Data item SBL doesn't appear in Business Function V0006JC and I'm note sure how to add it to the data structure for the P512000 form. I'm OK passing the BU number but in order for users to be able to view WO cost only a need to default the WO number into SBL.

Help

Louis