Can primers for PCR be duplicated?
Short answer: You need to buy some more, but you need the sequence also for ordering.

Long answer: The Taq polymerase needs a piece of DNA (or RNA) to prime the reaction and be able to enlarge the DNA chain, this is why we use primers in the first place (also to ensure reaction specificity to the region we want to amplify). To enable the reaction you would need a primer complimentary to the one you used of about the same length (or at least not much shorter), so this actually doesn't really make sense, because you would have to have a primer to make your primer. Since primers are cheap today, order some more.