Show original selling price on template (item table)

Show original selling price on template (item table)

Hi,

I'm trying to figure out how to get Zoho Books to generate a Commercial Invoice for international shipping. We've created a seperate invoice template to generate the Commercial Invoice before switching back to the Invoice template and sending the invoice. 

The last hurdle is that we have to show the original selling price (=item value) on the Commercial Invoice instead of the (manually altered) selling price on the SO/invoice (e.g. warranty replacement - invoice selling price=0 (manually altered) but the item value=x). Should be possible, as this information is stored for each item in the database.

I can (of course) add a customized field (e.g. item value), but how do I get Zoho to fill that field with the registered selling price?

Thanks in advance!