How can a User create a Descriptive Flexfield in the Subledger Spreadsheet

Summary:

The User would like a Descriptive Flexfield for the Subledger Spreadsheet with the source as receivables. Ideally, the User wants to create a column on the spreadsheet where the header reads 'Receipt Number'

Content (required):

Subledger Spreadsheet (Receivables Source)

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):