Can Invoice approval be separated by Invoices created from different Sources ?

Hello All,

We are planning our R12 upgrade and we plan to start to use Invoice Approval in R12.  We only want the invoices created manually for expense reports to go through the approval process. For our EDI invoices and Recurring invoices, we want them to be approved once they are created.  Is there a way to set up the AP workflow to function that way? Or we have to use AME (We are not using it so I am not sure how it works) ? Or it has to be done by Customization?

I think that we can use the Expense Report approval process and not use Invoice approval process. But my boss would like to also use Invoice approval process. So we want to get some inputs and suggestions regarding Expense Report approval process and Invoice approval process.