According to Wikipedia:
Customer experience (CX) is the sum of all experiences a customer has with a supplier of goods or services, over the duration of their relationship with that supplier. From awareness, discovery, attraction, interaction, purchase, use, cultivation and advocacy. It can also be used to mean an individual experience over one transaction; the distinction is usually clear in context.
User experience (UX) is the way a person feels about using a product, system or service. User experience highlights the experiential, affective, meaningful and valuable aspects of human-computer interaction and product ownership, but it also includes a person’s perceptions of the practical aspects such as utility, ease of use and efficiency of the system. User experience is subjective in nature, because it is about an individual’s feelings and thoughts about the system. User experience is dynamic, because it changes over time as the circumstances change.
Bottom Line: I think Customer Experience is not limited to human-computer interaction.