In GL report we do not get the "BILL NUMBER"filelds updated in print report and export (excel)
By bill number you mean the invoice number, right? It is shown in the Voucher column of the General Ledger.
When you convert it to PDF, you can pick columns of your choice.
Also, while exporting the report, the Against Voucher column gets fetched.
Hope this helps.
But we need need the report for entire trade debtors in a single report.