or download this
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"