If only a dot is a problem:

Sub M_snb()
  sn = Filter(Split(CreateObject("wscript.shell").exec("cmd /c Dir G:\OF\table_*.csv /b /s").stdout.readall, vbCrLf), ".")
     
  With CreateObject("scripting.filesystemobject")
    For j = 0 To UBound(sn)
      sp = Split(.opentextfile(sn(j)).readall, vbLf)
             
      For jj = 0 To UBound(sp) - 1
        sp(jj) = Log(Replace(Split(sp(jj), ",")(5), ".", ",")) / Log(10)
        If jj = 0 Then
          y = sp(jj)
        Else
          y = y + 100 * (sp(jj) - sp(jj - 1)) ^ 2
        End If
      Next
      c00 = c00 & vbLf & sn(j) & "|" & y
    Next
  End With
     
  MsgBox c00
End Sub