Account Coding Functionality - Initiate only selected invoices at the time of validation

We are looking to implement account coding functionality for the business and had a question regarding the current workflow setup.

At the moment, invoices are routed to a designated group of users. However, we would like to avoid sending all Non-PO matched invoices to this group. Is there a way to restrict the workflow so that only selected Non-PO invoices are routed for account coding?

Currently, the validation process is scheduled and automatically initiates the account coding workflow for all Non-PO invoices. We are hoping to introduce more control over which invoices trigger this step.