VERIFIED SOLUTION i

How to find out if you can add an OMR barcode to a PDF with PCE in DOC1 Generate

DOC1 PCE
You cannot add OMR barcode with PCE on PDFs.

However, you can make use of a tool called itext to achieve this. It is a free open source Pdf library for both C# or Java.
UPDATED:  November 10, 2017