File Search Criteria

I need help adding to the code below additional search criteria to look for only the Max file going by number order as below and with verbage after the number. I can't use lastmodified. Thanks in advance.

ABC0000555_1_1_ALL.xls
ABC0000555_1_2_ALL.xls
ABC0000555_1_3_ALL.xls(out of these files (I want this one)


This is the code I have so far:

Function FileSearch()
Dim i As Integer
Dim fs As Object
Set fs = Application.FileSearch
With fs
.LookIn = "C:\Documents and Settings\gaw2\My Documents\"
.fileName = "*.xls"

'.SearchSubFolders = True 'ADD THIS LINE to search the subfolders.
If .Execute(SortBy:=msoSortByFileName, _
SortOrder:=msoSortOrderAscending) > 0 Then
MsgBox "There were " & .FoundFiles.Count & _
" file(s) found."
For i = 1 To .FoundFiles.Count

'Debug.Print .FoundFiles(i)
' MsgBox .FoundFiles(i)
Next i

Else
MsgBox "There were no files found."
End If
End With

End Function

This is some code I think I can use but not sure how to incorporate into the code above or how it works:

brkFile = "": brkTest = "": brkMax = 0
For i = 1 To .FoundFiles.Count
  aTmp = Split(.FoundFiles(i), "_")
  If UBound(aTmp) = 3 Then
    curTest = aTmp(0) & "_" & aTmp(1)
    If curTest <> brkTest And i > 1
        MsgBox brkFile
        ' Your stuff here
        brkTest = curTest: brkMax = 0
    End If
    If CInt(aTmp(2)) > brkMax Then
      brkFile = .FoundFiles(i)
      brkMax = CInt(aTmp(2))
    End If
  End If
Next i
If brkMax > 0 Then
  MsgBox brkFile
  ' Your stuff here
End If