How do I populate values in the fields REFERENCE_2 & REFERENCE_3 in GL_JE_LINES table in Oracle Fusi

The currently, the above table has values in REFERENCE_1 for Vendor Name and REFERENCE_5 for Vendor Invoice #.
But the fields REFERENCE_2 & REFERENCE_3 are blanks. We would like to populate the values of Vendor Id & PO # into the fields REFERENCE_2 & REFERENCE_3 respectively in the table, GL_JE_LINES. Please provide the guidelines how to achieve to make use in our GL reports.