Arduino Serial Communication to mark events

Hello everyone! I’m using this [NEW-Free] Arduino Serial Communication Plugin “Serial COM v3”-(Fork from UE4Duino) - Community / Showcase - Epic Developer Community Forums (unrealengine.com) to mark events in my unreal game and analyse the brainwaves at those specific moments using EEG. Iam not exactly sure how to link all 3 together and how to mark those specific events, any idea? Thanks a lot