Tracking Workbook usage
 

I would like to track who opens a certain excel workbook. The macro below works great but only for those who have read/write permissions. It doesn't track users that have read-only permissions. The read-only permission is intended. Any ideas on what I need to do with the code? Thank you

Private Sub Workbook_Open(

Open ThisWorkbook.Path & "\TrackUsage.log" For Append As #
Print #1, Application.UserName, Now, "Opened
Close #

End Su