Function LastFile(ByVal startDate As Date, ByVal endDate As Date) As FileInfo
  Dim path As String = "C:\Temp"
 
  Dim dir As New DirectoryInfo(path)
 
  Return (From fi In dir.GetFiles() _
          Where fi.LastAccessTime >= startDate AndAlso _
                fi.LastAccessTime <= endDate).FirstOrDefault()
End Function

Ralf