Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic, and there are currently no FDA-approved medicines for treatment or prevention. Inspired by promising outcomes for convalescent plasma treatment, the development of antibody drugs (biologics) to block SARS-CoV-2 infection has been the focus of drug discovery, along with tremendous efforts in repurposing small-molecule drugs. In the past several months, experimentally, many human neutralizing monoclonal antibodies (mAbs) were successfully extracted from plasma of recovered COVID-19 patients. Currently, several mAbs targeting the SARS-CoV-2's spike glycoprotein (S-protein) are in clinical trials. With known atomic structures of the mAb and S-protein complex, it becomes possible to investigate in silico the molecular mechanism of mAb's binding with S-protein and to design more potent mAbs through protein mutagenesis studies, complementary to existing experimental efforts. Leveraging today's superb computing power, we propose a fully automated in silico protocol for quickly identifying possible mutations in a mAb (e.g., CB6) to enhance its binding affinity for S-protein for the design of more efficacious therapeutic mAbs.