If your original pathology slides are still available, Hopkins will do the PCR test on that material if there is no other tumor material available. Many centers do keep biopsy material, path slides etc. from cancer cases for a number of years (our local hospital, for example, keeps them 10 years) so an inquiry about this would not be out of the question.
If material can be located, then a visit to this Hopkins web site:
http://pathology.jhu.edu/labservices/hpv.cfm will give the instructions on how to arrange the test. In some case insurance may pay, however in light of your possible future eligibility for a therapeutuc vaccine it would be well worth the cost even if you had to pay yourself.
Gail