1. log into dynamics: https://uit.crm.dynamics.com/
2. click the name in the top left corner ie: 'project operations' to get the list of all apps
3. select the 'customer service admin' app
4. click case settings in the nav panel
5. next to "Automatic record creation and update rules" click 'manage'
6. click on 'New Support Auto Rules'
6a. (to make changes in the following step, this may first need to be temporarily deactivated by clicking 'deactivate' in the menu bar)
7. click 'New Support Auto Rules'
8. add your condition, save, then re-enable.