This is a simple example showing how you can use the VSTS RestFul API to access a test case and its test parameters, then use those parameters in test automation.
You will need to obtain a Personal Access Token, or PAT, from your VSTS instance. You can find details on how to do that here; https://www.visualstudio.com/en-us/docs/setup-admin/team-services/use-personal-access-tokens-to-authenticate.