Here are the steps for the automation:
1. If the Excel file created has a unique name everyday, then it's advisable to change that process to have a static name for the file. And as part of the same process, the first step that should be done is to rename the existing file by suffixing the file time stamp to it and archiving that file. The process should then create the Excel file with a static name.
2. The Tableau workbook can now read the data live from the network drive, or can be extracted daily per a schedule.