Credit Approval capability in AR

We purchase receivables for our customers from 3rd party. We have credit limit setup against the customers. If a customer has credit limit of $10000 and there is open receivable of $3000. Then available credit is $7000. Now if we decide to buy receivables worth $4500 for the customer there should be an approval number generated in the system and an outstanding approval of $4500 created against the customer. This outstanding approval should be deducted from available credit and available credit should be $2500. Is this possible in AR via out of the process?