Looking for some input on an easier way to do this. What's the best way to apply a credit when paying a set of invoices?

The set of ~100 invoices are from one vendor totaling 17k, with a credit of 12k, for a final balance of 5k.

Currently selecting some of the individual invoices to total the 12k credit, but it's taking quite a long time.

Thank you in advance for any detailed input!

Currently using quickbooks pro 2012 - yes we are upgrading asap.