Importing model (obj file) to project programmatically

My UE4 project has StaticMeshActor.

I need to make an application (bat file or exe), which will take obj file as a parameter.
This application should make the following changes in the project:

  1. Import this obj file to asset
  2. Replace existing StaticMeshActor with this new asset.

I had never before written similar applications.

Are there any suggestions how to do it?

I guess that it needs to use UE4 API, but I can not understand exactly how. It should be a plugin?