using PDI to pull from data already read into a variable?

I have written scripts to upload pdf files into mysql. I have the scripts
created to access those files and produce them for the user on the fly. All
well and good. Now I have a need to access one of those files and insert
its contents into a new pdf report. I have purchased the PDFlib+PDI and
want to pull the data from the variable returned from mysql. However, the
function for openning the pdf document to be inserted is looking for a file
on disk to access. Has anyone done this without writing the document to
disk first and then openning it from there? It seems that pulling it from
the db in a query and then "handing" it to the PDI functions would be less
intensive than writing it out, parsing it, and then ultimately deleting it
from disk again.

Any help would be greatly appreciated...

TIA

Larry