EBS Search String Clearing Document from Invoice Document

Hi,

I need to fetch the clearing/payment document from Invoice document number. Currently in MT940, the line 86 shows the invoice number only.

I have built a search string which will filter the invoice document number from line 86 and I intend to use it to trace the clearing/payment document number through standard algorithm. Following screen of the config. However system is not able to fetch the clearing document number. Any clue will be highly appreciated.

Best regds

Subha