Reference page: Service Functions – System (QTP, VBScript)

Description 

Check folder exists – check folder has files. Iterate through collection of files and keep reference of the most recently modified file (its DateLastModified property is always the highest number). The remaining reference is the one that you need. In case of errors the function returns Nothing. 

Note. In some cases, you may want to use DateCreated or DateLastAccessed properties.

Implementation

Public Function GetLastModifiedFile(ByVal sFolderPath)
  Dim FSO, objFolder, objFile
  Dim objFileResult, longDateTime
  Dim boolRC
 
  Set FSO = CreateObject("Scripting.FileSystemObject")
  boolRC = FSO.FolderExists(sFolderPath)
  If Not boolRC Then
    Set FSO = Nothing
    Set GetLastModifiedFile = Nothing
    Exit Function
  End If

  Set objFolder = FSO.GetFolder(sFolderPath)
  If objFolder.Files.Count = 0 Then
    Set FSO = Nothing
    Set objFolder = Nothing
    Set GetLastModifiedFile = Nothing
    Exit Function
  End If
 
  Set objFileResult = Nothing
  longDateTime = CDate(0)
 
  For Each objFile in objFolder.Files
 
    If objFile.DateLastModified > longDateTime Then
      Set objFileResult = objFile
      longDateTime = objFile.DateLastModified
    End If
   
  Next
 
  Set FSO = Nothing
  Set objFolder = Nothing
  Set GetLastModifiedFile = objFileResult

End Function