Dear Gary, We were not able to find your form on the Clerk of Court's website either. However, we found one on the Pinellas County site, so you can see what it looks like. We suggest that you go to the courthouse and ask the clerk for the form. If the clerks are unable to provide it to you go to the law library.
A witness subpoena form is very simple and straight forward. However it needs to conform to your circuit/ county, not only on the header, but there is also an ADA Notice which is specific to the circuit. I found the Pinellas -