Thanks Cliff.  I have installed your script and tokens exactly as you have described.  The script does not return any errors when built and the workflow publishes OK.  However when I run the workflow the command does not run.  The workflow completes OK.  There are no errors.

I have added a Pause to the C:\renamefile.bat but there is no indication that it has been run.

If I use SDKScript instead of Script I can return the ProcessID as a token.

I basically don't know why the command won't run, but I am also only a beginner when it comes to script.

Could you please have a quick look at the following and let me know if it matches what worked for you?

This is my complete code using the Workflow Script activity:

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Data.SqlClient
Imports System.Text

Namespace WorkflowActivity.Scripting.Script
    '''<summary>
    '''Provides one or more methods that can be run when the workflow scripting activity is performed.
    '''</summary>
    Public Class Script1
        Inherits ScriptClass90
        '''<summary>
        '''This method is run when the activity is performed.
        '''</summary>
        Protected Overrides Sub Execute()
            'Write your code here.
            Dim processID As String = ""
            Dim stdOut As String = ""
            Dim exitCode As String = ""

            'Create a process (which will not start running until later) which will eventually start the program we wish to call.
            Using process As System.Diagnostics.Process = New System.Diagnostics.Process

                Try

                    'Retrieve the token values...
                    Dim cmdLineParameters As String = Me.GetTokenValue("CmdLineParameters")
                    Dim externalProgram As String = Me.GetTokenValue("ExternalProgram")
                    Dim waitForExit As Boolean = Me.GetTokenValue("WaitForExit")

                    ' Empty externalProgram token is ignored...
                    If (Not String.IsNullOrWhiteSpace(externalProgram)) Then

                        'These settings let us specify the file name and location, and specify to the process that we wish to handle stdout and stderr ourselves. UseShellExecute = false is
                        'a requirement for this to work.
                        process.StartInfo.UseShellExecute = False
                        process.StartInfo.RedirectStandardOutput = True
                        process.StartInfo.FileName = externalProgram

                        'If there are command line arguments then set them...
                        If (Not String.IsNullOrWhiteSpace(cmdLineParameters)) Then
                            ' The arguments are specified in the input property box
                            process.StartInfo.Arguments = cmdLineParameters
                        End If

                        'Starts the process with all the settings we chose via Process.StartInfo...
                        process.Start()

                        'Set the processId variable for return as a token...
                        processID = process.Id

                        'If True then wait for the process to terminate before continuing the workflow...
                        If (waitForExit) Then
                            'As recommended in http://msdn.microsoft.com/en-us/library/system.diagnostics.process.standardoutput%28v=vs.71%29.aspx, stdout should be read before
                            'WaitForExit. Here the stdout is read and stored, and then we wait for the process to complete, if applicable.
                            Dim output As String = process.StandardOutput.ReadToEnd
                            process.WaitForExit()

                            'Set the return values to return as tokens...
                            stdOut = output
                            exitCode = process.ExitCode

                        End If

                    End If

                Finally
                    'Once we are done, make sure to free the process' handle if the process exists.
                    If (Not process Is Nothing) Then
                        process.Dispose()
                    End If
                End Try

            End Using

            'Set the token values to be evaluated later in the workflow...
            Me.SetTokenValue("ProcessID", processID)
            Me.SetTokenValue("StdOut", stdOut)
            Me.SetTokenValue("ExitCode", exitCode)



        End Sub
    End Class
End Namespace

 My Tokens are the same as yours:

My batch file C:\renamefile.bat works when run from Windows:

rename MyFile.csv NewName.csv
Pause

Have I installed the script correctly?

Thanks in advance for you help. Any feedback would be appreciated.