This method allows you to insert raw postscript at any point in the postscript document.
You can use this function to include 'Barcodes in pure PostScript' in the prolog of your postscript document, and then create a temporary file that contains the necessary postscript to actually call the barcode generating postscript function at whatever point in your document you want it to appear.
it would be nice if there was an alternate form of this function that allowed you to just insert the raw postscript other than make a temporary file to be opened by the function.
