Handling PDF/A files.

One of my credit card statements is supplied in PDF/A format.
I use Hazel to hand my PDFs to PDFPen 7.3.4 for OCR processing. PDFPen bleats about not being able to handle PDF/A (because it can't alter the contents), and recommends I:
1. Lock the original.
2. Duplicate the original.
3. Run OCR on the duplicate.
How can I use Hazel to perform steps 1 and 2, and then run 3 on the duplicate?
I use Hazel to hand my PDFs to PDFPen 7.3.4 for OCR processing. PDFPen bleats about not being able to handle PDF/A (because it can't alter the contents), and recommends I:
1. Lock the original.
2. Duplicate the original.
3. Run OCR on the duplicate.
How can I use Hazel to perform steps 1 and 2, and then run 3 on the duplicate?