print multiple pages in a single page

Thank you Barlae for your guidance, the acrobat JS API is so usefull

I use action wizard with sendkeys method, it was quite usefull but I guess to do directly will be easier to automatize

However I'm not a programmer and I'm used to get stuck at the first stone in my way.

This is what I have edited from another instructions which allows to add a watermark to the pdf (another thing it is required) I hoped that it works fine then I realize that even if it works I don't know how to command to print the merged sheets on a file

Sub printmerged()
Dim acroApp As Acrobat.acroApp
Dim AVDoc As Acrobat.AcroAVDoc
Dim myDocument As Acrobat.AcroPDDoc
Dim jso As Object

Dim strPath As String
Dim strFileName As String
Dim intPages As Integer
Dim i As Integer

Set acroApp = CreateObject("AcroExch.App")
Set myDocument = CreateObject("AcroExch.PDDOc")

strPath = "C:\"
strFileName = "1.pdf"

'Open file and load JSObject
Set myDocument = CreateObject("AcroExch.PDDOc")
myDocument.Open (strPath & strFileName)
Set jso = myDocument.GetJSObject

jso.printparams _
nUpNumPagesH:=10, _
nUpNumPagesV:=14

Print myDocument

'Clean up
Set jso = Nothing
Call acroApp.CloseAllDocs
Set myDocument = Nothing
Call acroApp.Exit
Set acroApp = Nothing

End Sub