Thx Gmayor for your answer.
I added few lines to my code, so when the log file is open the file fullname, the user name , and the date are automatically filled, the user just need to add a description of the modification.
base on that the simplest way i think would be the
start Excel open the log, write the data, save the log and close it
excel file is simply a 4 columns sheet with file fullname(of the monitored file), the user name , the date , and modification description
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Dim Confirm As VbMsgBoxResult
Application.EnableEvents = False
Cancel = True
Confirm = MsgBox("Do you need to updtate de log book?", vbYesNo)
If Confirm = vbYes Then
Set monitoredDoc = ThisWorkbook
Set historyWb = Workbooks.Open("C:\Users\Vincent\Desktop\Excel-Malin\test1.xlsx")
Set historyWks = historyWb.Worksheets(1)
Dim chemin As String
chemin = monitoredDoc.FullName
With historyWks
nextRow = .Cells(.Rows.Count, "A").End(xlUp).Offset(1, 0).Row
End With
With historyWks
With .Cells(nextRow, "C")
.Value = Now
.NumberFormat = "mm/dd/yyyy hh:mm:ss"
End With
.Cells(nextRow, "B").Value = Application.UserName
.Cells(nextRow, "A").Value = chemin
End With
Else
ThisWorkbook.Save
End If
Application.EnableEvents = True
End Sub