There is a very old trick that worked with Access 2002-2003 where you would basically switch the default printer to your PDF creator, print the report, and then switch the default printer back to the original one.

' get the current default printer & save it using

Dim DefaultPrinter As String

DefaultPrinter = Application.Printer.DeviceName

' change the default printer to your PDF creator using

Dim PrinterString As String, prt As Printer

PrinterString = "Acrobat PDFWriter"

Set prt = Application.Printers(PrinterString)

Set Application.Printer = prt

' open the report in preview, and then print the report to PDF

DoCmd.SelectObject acReport, Reports(0).Name, False

DoCmd.PrintOut

Do While Reports.Count <> 0

DoEvents

Loop

' restore the original printer

PrinterString = DefaultPrinter

Set prt = Application.Printers(PrinterString)

Set Application.Printer = prt