1) Assuming you're using Adobe PDF (or the earlier Acrobat Distiller) driver,
you can set it up not to ask for a file name;  it automatically creates a new
name for the PDF based on comments the source app puts in the PS output.  

Give it a try.  It's nice and simple but not always acceptable for several
reasons.  

2) You can print to a PS driver and send the results To File then
programmatically invoke Distiller to convert the PS file to a PDF.  This was
fairly simple to do and documented by Adobe and others for versions through
Acrobat 5.  Adobe broke it with Acrobat 6 and doesn't document the changes;  
they want you to sign up for their developer program to get documentation.  

3) Print to PS and use GhostScript instead of Distiller.

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Ooops.  One more:

4) You might be able to use Distiller's Watched Folders feature to
automatically distill PS files that you programmatically print to a watched
directory.  This used to be fairly easy to set up;  in Acrobat 6, the watched
folders feature seems to have become a lot crankier than it used to be.  

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