This example adds the user's email alias and the current date to the project Comments field whenever the project is opened. Placing this example in the Open event of a project provides a simple access history for the file.
Private Sub Project_Open(ByVal pj As MSProject.Project)
Dim Alias As String
Alias = InputBox$("Please enter your e-mail alias: ")
pj.ProjectSummaryTask.AppendNotes vbCrLf & "Opened by " & Alias & _
" on " & Date$ & "."