I don't think it's possible, I just know it's possible to dump it to a local temp location and open it automatically. Still requires the user to print though.
The applescript should be pretty simple though, and you can probably find a "send event" equivalent if you need winOS compatibility as well.
I export the file using Get ( TemproaryPath) then Send Event ( "avet" ; "pdoc" ; "$Path" ) which on the Mac uses Preview to print the PDF
Then I have an if statement that tests for the Mac Platform and if so runs a Preform AppleScript ["tell application "Preview" to quit"]