Search string to replace Reference key 1 field in accounting documents

Hi Experts,

We are using MT940 as file type for electronic bank statement now as per new requirement from business that UTR number(highlighted in below Screenshot) should be appeared somewhere in accounting document .

I am exploring the option of search string to Copy this with target field BSEG-XREF1.

1. Please advice if it is possible via search string or we need to go with enhancement in code

2. If possible can you suggest the mapping, I have tried below mapping with help of some blogs but it is not working.

Regards,

Praveen Prajapat