Insert batch of pictures into Powerpoint slides sorted by name

Hi ! I am new at VBA, and I have been trying to find a code to insert a batch of pictures into Powerpoint (2010) slides sorted by name. I found this code on http://www.pptfaq.com/FAQ00352_Batch..._per_slide.htm which works fine but it seems to be inserting the pictures a random order, I want the pictures to be sorted alphabetically by name like I see them when I go into the folder. Here is the code:

Private Sub CommandButton24_Click()

Dim strTemp As String
Dim strPath As String
Dim strFileSpec As String
Dim oSld As Slide
Dim oPic As Shape

' Edit these to suit:
strPath = "H:\Pictures\"
strFileSpec = "*.*"

strTemp = Dir$(strPath & strFileSpec)

Do While strTemp <> ""
    Set oSld = ActivePresentation.Slides.Add(ActivePresentation.Slides.Count + 1, ppLayoutBlank)
    Set oPic = oSld.Shapes.AddPicture(FileName:=strPath & strTemp, _
    LinkToFile:=msoFalse, _
    SaveWithDocument:=msoTrue, _
    Left:=0, _
    Top:=0, _
    Width:=-1, _
    Height:=-1)
    ' width/height of -1 tells PPT to import the image at its "natural" size

' Optionally, make it fill the slide - even if that means changing the proportions of the picture
' To do that, uncomment the following:
  With oPic
      .LockAspectRatio = msoFalse
      .Height = ActivePresentation.PageSetup.SlideHeight
      .Width = ActivePresentation.PageSetup.SlideWidth
  End With

' Optionally, add the full path of the picture to the image as a tag:
With oPic
  .Tags.Add "OriginalPath", strPath & strTemp
End With

    ' Get the next file that meets the spec and go round again
    strTemp = Dir$
Loop

End Sub

The file names I want in order are in this format: Image3, Image 4, Image 9, etc.

Thank you so much!