Is there any efficient way to insert a page in pdf via VBA?

Hi there,

I am using PDDoc.InsertPages to insert 01 pdf page to another 400 page pdf and it takes about 5 minutes. Is there any other way to do it more efficiently? After all, it's only 01 page insert.

My environment is excel 2010 and Acrobat X Pro.

Here is my code and it works well except too slow!!!

Public Function MergePDF(SourceFile, TargetFile, MergedFile)

    On Error GoTo Error

    Dim AcroApp As Acrobat.AcroApp

    Dim Part1Document As Acrobat.AcroPDDoc

    Dim Part2Document As Acrobat.AcroPDDoc

    Dim numPages As Integer

    Set AcroApp = CreateObject("AcroExch.App")

    Set Part1Document = CreateObject("AcroExch.PDDoc")

    Set Part2Document = CreateObject("AcroExch.PDDoc")

    Part1Document.Open (SourceFile)

    Part2Document.Open (TargetFile)

    ' Insert the pages of Part2 after the end of Part1

    numPages = Part1Document.GetNumPages()

    If Part1Document.InsertPages(numPages - 1, Part2Document, 0, Part2Document.GetNumPages(), True) = True Then

        Call Part1Document.Save(PDSaveFull, MergedFile)

    End If

    Part1Document.Close

    Part2Document.Close

    AcroApp.Exit

    Set AcroApp = Nothing

    Set Part1Document = Nothing

    Set Part2Document = Nothing

    Exit Function

Error:

End Function