Hi,
based upon this thread https://forums.unrealengine.com/t/load-static-mesh-with-path-in-c/292234/2 you should be able to do something like this to load existing meshes through c++
TSubobject<UStaticMeshComponent> mesh = PCIP.CreateDefaultSubobject<UStaticMeshComponent>(this, TEXT("Mesh"));
const ConstructorHelpers::FObjectFinder<UStaticMesh> MeshObj(TEXT("/Game/Mesh/Cube/YourMesh"));
mesh->SetStaticMesh(MeshObj.Object);