Thank you for contacting Clarizen. This is possible using a custom workflow that runs on Resource and will trigger when a Customer is added (related object). In order for you to get best assistance for customization questions please do the following...
1 - Post this question in the Customizations section of the Forum.
2 - For further clarification, we suggest you register for one of our daily Q&A webinars (see the link-> http://www.clarizen.com/resources/online-demo.html#second ).These are great resources for free consulting with our Customer Success Managers and visual answers to your questions. One of our experts will be able to explain it in detail in a much faster manner.