Project Supplier Invoice Account Generator(PAAPINVW) Workflow Issue

Currently, the Project Supplier Invoice Account Generation (PAAPINVW) Item Type Workflow does not contain an Item Attribute to store the VENDOR_SITE_ID of the Payables invoice.

We just need to add the VENDOR_SITE_ID field value as Item Attribute in the Workflow so that their custom program can retrieve the value from it during the workflow process. In addition, the calling program that initiates the workflow will also need to set the value into the workflow item attribute.

Has anybody encountered this issue and how did you get around it?