It is always fun and instructive to figure out one of snb's codes.

I tried to make this verbose and simple enough that eve a Czech, (home of the Tatra ,) Statistical Analyst can figure it out

If it errors, please note the error statement and number for us.

Place this code in a standard Module, Edit the FolderPath Constant to fit. After you see the Message "IT Works! Stopping Sub" Then code your next formula and run it again. The Message shows after only10 files have been successfully processed. When the code is complete and runs all the way to the message, remove the "For Testing Only" section at the bottom.

To run the Sub, make sure an empty sheet is visible in Excel, then in the VBA, put the mouse cursor anywhere in the sub and press F5. BTW, Press F8 to step (run) through the code one line at a time. If you do that, you can hover the mouse over a variable to see its Value at that time.

Option Explicit



Sub SamT_snb()

Dim Filename As String
Dim NameLength As Long

Dim FileNameArray As Variant                'sn
Dim FileLinesArray As Variant                     'sp

Dim Formula1LinesArray As Variant
Dim Formula1Result As Double                       'y
  'Repeat these two lies for each Formula. Edit the numbers to suit
Dim Formula2LinesArray As Variant
Dim Formula2Result As Double

Dim Fn As Long 'Fn = Index number for FileNameArray                     'jj
Dim Fl As Long 'Fl = FileLinesArray Index number                                    'j

Const FolderPath As String = "The Path to your folder must go here\" 'include ending \


'''' Put all the file names in the path in Array
  FileNameArray = Filter(Split(CreateObject("wscript.shell").exec(FolderPath & "*.csv /b /s").stdout.readall, vbCrLf), ".")
  
  '''' Open one file at a time
  With CreateObject("scripting.filesystemobject")
    For Fn = 0 To UBound(FileNameArray)
      

''''Put all lines from one file in Arrays
      FileLinesArray = Split(.opentextfile(FileNameArray(Fn)).readall, vbCrLf)
      Formula1LinesArray = FileLinesArray
      Formula2LinesArray = FileLinesArray
      'Initializ
      Formula1Result = 0
      Formula2Result = 0
''''Calcuate first result for one file
     For Fl = 0 To UBound(FileLinesArray)
     
'''' Calculate first formula
        'Replace file line with Log of 6th value. Split(BlahBlah)(5)
        Formula1LinesArray(Fl) = Log(Split(Formula1LinesArray(Fl), ",")(5))
          'After the first line
        If Fl > 0 Then Formula1Result = Formula1Result + Formula1Result + _
          (Formula1LinesArray(Fl) - Formula1LinesArray(Fl - 1) ^ 2) * 100
        
'''' Calculate second Formula here
              'Replace file line with first part of formula. Think carefully
         'Formula2LinesArray (Fl) =  Your formula here
        
      Next Fl
       
'''' Put results in sheet

    'Get FileName
      NameLength = Len(FileNameArray(Fn)) - InStrRev(FileNameArray, "\")
      Filename = Right(FileNameArray(Fn), NameLength)
      
       'Place result
      With ActiveSheet.Rows(Fn + 1)
        .Columns(2) = Formula1Result 'Column B
        .Columns(3) = Formula2Result
        .Columns(4) = Filename
        End With
        
        'Initialize Arrays
        FileLinesArray = ""
        Formula1LinesArray = FileLinesArray
        Formula2LinesArray = FileLinesArray
      
''''' For testing only
If Fn >= 100 Then
  MsgBox "IT Works! Stopping Sub"
  Exit Sub
End If
''''End Test

    Next Fn 'Work on next File
  End With
End Sub