Hello freik,
Your options are limited in accomplishing this task. If you are hosting the website on your own server or have access to the hosting server, you can print the PDF from the command line of the server. You would need to use a combination of the following:
PDFCreator (free), Adobe Acrobat (not free), or a similar utility that can print PDF files from the command line.
Scripting.FileSystemObject
WScript.Shell
Server.MapPath
You'll need to have a template document set up on the server that you can open up and replace values to, then save it to another file. You may or may not need to use Server.MapPath. Once the file is written with values, you'll have to pass a command to the WScript.Shell object to print the file to a PDF. After that, it's a matter of getting the document displayed to the user.
Regards,
Ax