How can I separate the Validate Invoice functionality from Invoice creation?

We want to segregate the duties of 2 groups of people to prevent fraudulent activity. We want to remove the ability to Validate Invoices for anyone who can create invoices and separate the validation part of the process out to a different user with a different responsibility. I've tried adding functions to the View Only menu and it doesn't seem to be able to provide the Validate options in the invoice batch or invoice form without giving the ability to create invoices. Is there a way to do this?

Thanks in advance!