Invoking powershell command

// create Powershell runspace
            Runspace runspace = RunspaceFactory.CreateRunspace();
            // open it
            runspace.Open();         
            Command cmd = new Command("Get-Credential");
            cmd.Parameters.Add("Credential", "user");
            // create a pipeline and feed it the command
            Pipeline pipeline = runspace.CreatePipeline();
            pipeline.Commands.Add(cmd);
            // execute the commnand
            Collection<PSObject> results = pipeline.Invoke();
            // close the runspace
            runspace.Close();