ok no problem, goodluck.
Public Function ActualCombine(ByVal sPath As String, sOutFile As String) As Integer
'
' sPath is the path (folder) where your all pdfs exists
' sOutfile is the name of your output pdf (example, "Output.pdf")
    Dim sFile As String
    Dim cmd As String
    Dim dict As Object
    Dim i As Integer, j As Integer
    Set dict = CreateObject("scripting.dictionary")
    sPath = Replace$(sPath & "\", "\\", "\")
    'put all the .pdfs in the dict object
    sFile = Dir$(sPath & "*.pdf")
    While Len(sFile) <> 0
        dict(sFile) = 1
        sFile = Dir$
    Wend
    j = -1
    'check if there is any pdf
    If dict.Count <> 0 Then
        For i = 0 To dict.Count - 1
            'find Output.pdf
            'delete it only if there are other pdfs,
            'otherwise, leave it
            If dict.keys()(i) = sOutFile And dict.Count > 1 Then
                Kill sPath & sOutFile
                j = i
            End If
        Next
    End If
    ' if we delete Output.pdf, remove it from the
    ' pdf list
    If j > -1 Then
        dict.Remove (dict.keys()(j))
    End If
    ' recheck it again
    If (dict.Count = 0) Then
    ElseIf (dict.Count = 1 And dict.keys()(0) = sOutFile) Then
    Else
        cmd = "pdftk.exe " & sPath & "*.pdf cat output " & sPath & sOutFile
        Shell cmd, vbHide
        
        'now delete all pdfs on the list
        For i = 0 To dict.Count - 1
            Kill sPath & dict.keys()(i)
        Next
        ActualCombine = dict.Count
     End If


    Set dict = Nothing
End Function




' this is the test sub
' to test CombinePDF() function
Public Sub CombinePDF()
    Dim sPath As String
    sPath = "C:\MIHAI\DOC\ASIG\DOSARE"
    'sPath = Environ$("userprofile") & "\documents\"
    'call the combine pdf routine
    If ActualCombine(sPath, "Output.pdf") <> 0 Then
        MsgBox "Pdfs combined to Output.pdf"
    Else
        MsgBox "No new pdf have been combined"
    End If
End Sub