I am wanting to auto refresh extracts without installing Tableau Server. Just a desktop and prep installation. All the scripts examples reference Tableau Server or Tableau online. Has anyone accomplished this automation?

Syntax and parameters for the tableau refreshextract command

Use 

tableau refreshextract

 to refresh an extract on Tableau Server or Tableau Online. Refreshing an extract updates an existing extract with any modifications that have been made to the data source since the last refresh.

To see help for this command, at the Windows command prompt, type the following command:

It only references Server or Online, not local.

As I thought about it, what I really need to do is refresh an extract and repackage a workbook automatically.

The extract is not created in prep, it is a live connection to the data, and then I create an extract within Desktop.