You wanted to know the steps to add any extension field to the Upload template excel for example Supplier invoice upload excel.
SAP Business ByDesign
This shall not be done in standard system as of now and thus it has to be done by Partners.
Please contact your partners to go through the details given in the document attached to resolve this issue.
add extension fields to excel,How to add extension fields,extension field , KBA , AP-SIP-SIV , Supplier Invoice , AP-POP-PO , Purchase Order , Problem
|Adding ext fields to excel.pdf|
|How to add the extension field in Excel.docx|