HOW CHECK FILE.NAME HAS EXISTS OR NOT IN FOLDER,if not exists then copy

I HAVE CODING LIKE this,using workbook open ,if file in folder has copy or file has exists ,for next time not to calculate or not copy again
else if in folder contain new file ,every workbook_open new file in sheet1.usedrange copy to resume file sheets("REKAP")
HOW TO do check up file exists or not exists
i have coding ,every file in folder has copy ,i am save filename in sheets.rekap columns("O")
how to do thank for attention

Private Sub Workbook_Open()
Dim fso As Object, f As Object, sf As Object, ssf As Object, myFile As Object
Dim WB As Workbook, j As Long, n As Long, i As Long, x(), mytable, SP
Dim s As String, temp As String, rg As Range
Set fso = CreateObject("Scripting.filesystemObject")
Set f = fso.GetFolder("C:\Users\wawang-pc\Documents\Locked\te\fileku\Gabungfile")
'GANTI PATH SESUAIKAN
 With Sheets("REKAP")
     If Not rg Is Nothing Then Set rg = Range("O1", .[O100000].End(3))
     If Not rg Is Nothing Then
         SP = Split(Join(Application.Transpose(rg.Value), ","), ",")  ' i want check up is file has copy or not,if in folder there are new file then copy range from new file
     Else
         GoTo n1
     End If
 End With
Application.ScreenUpdating = False
For Each sf In f.SubFolders
      Set ssf = sf
    For Each myFile In ssf.Files
     If myFile.Name Like "*DIKLAT*" Then
        For n = 0 To UBound(SP)
            If Not fso.FileExists(SP(n)) Then         ' IF FILE DOESN EXISTS IN FOLDER THAN COPY RANGE  FROM NOT EXISTS FILE
n1:
                    j = j + 1
                    ReDim Preserve x(1 To j)
                    Set WB = Workbooks.Open(SP(n), False)
                    With WB.Sheets("REKAP")
                         mytable = .UsedRange.Offset(1).Value
                          x(j) = mytable: mytable = ""
                          s = IIf(s = "", myFile, s & "," & myFile)         's = path of every file and save to range
                         .Parent.Close savechanges:=False
                    End With
             Else
               GoTo nn
             End If
           Next n
   End If
 
Next myFile, sf
For i = 1 To UBound(x)
   With Sheets("REKAP")
    Range("A100000").End(3)(2).Resize(UBound(x(i)), UBound(x(i), 2)) = x(i)
   End With
Next i
    With Sheets("REKAP")
       .Cells(Rows.Count, "O").End(3)(2).Resize(n) = Split(s, ",")   'SAVE PATH TO columns O
    End With
    Erase x
nn:
    MsgBox "Tidak ada tambahan file Baru di folder ", 64: Exit Sub
    Exit Sub: Application.ScreenUpdating = True
End Sub

this other code but still can copy if has exists

Sub ff()
Dim d As Object, fso As Object, wb As Workbook, rg As Range, r As Range
Set d = CreateObject("scripting.dictionary")
Set fso = CreateObject("scripting.Filesystemobject")
Dim t, a(), j As Long
For Each f In fso.getfolder("C:\Users\wawang-pc\Documents\Locked\te\fileku\Gabungfile\DATA").Files
  d(f) = ""
Next f
If Not rg Is Nothing Then
   Set rg = Columns(12).SpecialCells(2)
   For Each r In rg
      If d.EXISTS(r.Value) Then
       MsgBox d(r.Value)
       d.Remove r.Value
      Else
         For Each E1 In d
           Set wb = Workbooks.Open(E1, False)
           j = j + 1
           ReDim Preserve a(1 To j)
           a(j) = wb.Sheets("REKAP").UsedRange.Offset(1)
           wb.Close False
           Cells(Rows.Count, 12).End(3)(2) = E1
           MsgBox "file exists "
         Next E1
      End If
   Next r
 
Else
        For Each E In d
           Set wb = Workbooks.Open(E, False)
           j = j + 1
           ReDim Preserve a(1 To j)
           a(j) = wb.Sheets("REKAP").UsedRange.Offset(1)
           wb.Close False
           Cells(Rows.Count, 12).End(3)(2) = E
           MsgBox "file not exists "
        Next E
     
End If

Dim i As Long
For i = 1 To UBound(a, 1)
    With Sheet1
       .Cells(Rows.Count, 1).End(3)(2).Resize(UBound(a(i), 1), UBound(a(i), 2)) = a(i)
    End With
Next i
Erase a: j = 0
End Sub