Handling audio source (Unity + Vuforia)

Hello everybody, I´m driving myself crazy with this, hopefully somebody will be able to guide me.

I have an AR app (Android), made it with Unity and Vuforia.

In this app, I have a background sound from the very start of the app, and a paused video. What I want to accomplish is that when I play the video, the Audio Source of the background sound stops. And opposite: when the video is paused, that background sound must start playing again.

Problems: 1. I don´t know C#, so I start to tackle this with a JS script. No luck so far. 2. Trying to unlock the problem touching the Vuforia´s C# scripts, I couldn´t print to screen a Debug.Log message to track the script position to insert a test line... 3. Even with a webcam connected, Vuforia doesn´t allow to preview the video file in the "Game" windows, in Unity.

Hopefully, somebody will be able to help me

Thank you very much in advance to you all,l guys!