Show DFF (PO Header Attributes) in Signature Block in Purchase Contract

Good Day.

I have been trying to print the information that is stored in the PO Header's DFF in the Signature block located in the Contract that is generated via PO Output for Communication concurrent, I have been searching at MOS and in other places the way to add this information to the template OKCTERMS_en.xls (custom XX_OKCTERMS_en.xls) in order to pass thar information to the .rtf template, Is it necesary to update or modify other file?

thanks.