My itunes on my laptop is connected via airport express to my analog stereo system. It has 3 zones and is currently controlled

[jjsavageca]

Connecting iTunes via Airport Express to an Analog stereo and controlled with an Amazon Echo or Dot via Alexa Voice control

 

[Alabalcho]

May be you have to rephrase your question, what you have, and what you want to achieve?

Alexa / Echo / Dot is not the best choice for locally stored content.