How to find Status of a Vendor Invoice?

I would like to query for Vendor Invoices of a particular status. In other words, we want to pick up on the Status field on a printed Work Order Cost / Vendor Invoice.

For example, Status = "Approved R&M>$1000.00".

I know the data for Vendor Invoice is located in the WorkOrderCost object. I can pick up WorkOrderCost fields such as Number, VendorInvoiceDate, VendorINvoiceTotal, etc, and can query on the related FinanceItem records as needed.

Can you point out which variable represents the WorkOrderCost status as we see it on the printed Vendor Invoices? The variables with a "Status" such as CostStatusId = 1 or CostState = PENDING don't match up with "Approved R&M>$1000.00", so it must be some other variable.

Thanks,
-Ed