'Add a user to a group
Public Sub AddUser2Group(strUser As String, _
        strGroup As String)
    Dim wrk As DAO.Workspace
    Dim usr As DAO.User
    Dim grp As DAO.Group

    Set wrk = DBEngine(0)
    On Error Resume Next

    'Create object references
    Set grp = wrk.Groups(strUser)
    Set usr = grp.CreateUser(strUser)

    'Add the group to the user's Groups collection
    grp.Users.Append usr
    grp.Users.Refresh

    Set usr = Nothing
    Set grp = Nothing
    Set wrk = Nothing
End Sub