That I am aware of a product that does this.
You are looking for a third party app that takes pdfs generated from AS/400 spooled printouts and prints them to an AFP / IPDS printer? It might be useful - I looked around and didn't see anything - I'll look around later, though.
I assume you want to print non-400 generated pdfs, too - or can you retain the spooled files you used to create the pdfs and just print THAT out when you want?