Should be possible by using a macro in Docman that executes when the document is viewed. I asked ChatGPT for a solution:

Help me create a VBScript program that adds a watermark to an existing PDF file. It's okay if the VBScript need to call out to other programs installed on the same machine.

Here's the reply:

===== BEGIN CHAT WITH CHATGPT =====

Adding a watermark to a PDF file using VBScript directly can be challenging because VBScript doesn’t have native support for manipulating PDFs. However, you can use VBScript to call other programs that handle PDFs, such as Adobe Acrobat or a third-party PDF manipulation tool like PDFtk or Ghostscript.

Here’s a basic example of how you can use VBScript in conjunction with PDFtk, a command-line tool for manipulating PDFs. First, you'll need to download and install PDFtk from here.

Once you have PDFtk installed, you can use the following VBScript to add a watermark to your PDF file:

' Define the paths to the input files
Dim inputPDF, watermarkPDF, outputPDF, pdftkPath

' Path to the PDF files and PDFtk executable
inputPDF = "C:\path\to\your\input.pdf"
watermarkPDF = "C:\path\to\your\watermark.pdf"
outputPDF = "C:\path\to\your\output.pdf"
pdftkPath = "C:\path\to\pdftk.exe"

' Create the command string
Dim command
command = """" & pdftkPath & """ """ & inputPDF & """ background """ & watermarkPDF & """ output """ & outputPDF & """"

' Create a WshShell object to run the command
Dim shell
Set shell = CreateObject("WScript.Shell")

' Execute the command
shell.Run command, 1, True

' Clean up
Set shell = Nothing

Explanation:

1. Set Paths: Replace the paths in inputPDF, watermarkPDF, outputPDF, and pdftkPath with the actual paths to your files and the PDFtk executable.
2. Build Command: The command variable constructs the command line for PDFtk. It tells PDFtk to use the watermark PDF as a background for the input PDF and save the result to outputPDF.
3. Execute Command: The WshShell object runs the constructed command and waits for it to complete (True in the Run method makes the script wait).

Important Notes:

• Ensure the paths do not contain any spaces or, if they do, that they are correctly quoted.
• This script assumes PDFtk is installed and accessible at the given path.
• You may need to adjust the PDFtk command options based on your specific needs. For more options and details, refer to the PDFtk documentation.

==== END CHAT ====

The above is completely untested and using any of it should be done at your own risk. That being said, the replies are usually a good start and you should be able to create a macro in Docman that calls out to PDFtk, in this case. I'm sure there are other tools that can do the same thing.

Good luck!