try to adapt this excel example

# Save as PDF
$Excel->ActiveWindow->SelectedSheets->PrintOut({
               Copy => 1,
               ActivePrinter => 'Acrobat PDFWriter'});

# Save as Excel
$Book->SaveAs({Filename =>'C:\report\results\check_all.xls',
              FileFormat => xlWorkbookNormal});  
$Book->Close();
$Excel->Quit();
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or this vb Save Current PDF File Using OLE in VB Application

Set AcroExchApp = CreateObject("AcroExch.App")
Set AVDoc = AcroExchApp.GetActiveDoc
Set PDDoc = AVDocTarget.GetPDDoc

If PDDoc.Save(PDSaveFull, "c:\test.pdf") = False Then
   MsgBox "Unable to save image"
Else: MsgBox "The file is saved"
[download]

Might be easier if you used an ole browser to see adobe API