Can I generate trial invoice xml using trial invoice poid instead of bill poid?

After generating trial invoice, I want to export the invoice xml stored in BLOB object in invoice_formats_buf_t.

I know there is an utility pin_inv_export when run as below generates an xml.

"pin_inv_export -trial -end 10/19/2018 -detail bills.txt -verbose".

bill.txt looks like:

0 PIN_FLD_RESULTS                  ARRAY [0]

1     PIN_FLD_POID                  POID [0] 0.0.0.1 /bill 32485548 1

Issue 1: If the same bill has multiple trial invoices generated on same date, I would like to generate xml only for the latest trail invoice generated.

I tried by giving trial invoice poid in bills.txt but did not work. Is there a way to generate xml file using trial invoice poid and store it in a directory ?