I need to specify a filename for my pdf

Hi, I'm new to the forum. I'm generating a PDF directly from a database report, using the PDF Creator printer driver. The PDF is created with the name of the print job () and I then have to rename it to give it its proper unique name. For example, if the procedure that generates an invoice is called InvoiceGen, I get a pdf called InvoiceGen.pdf. I then have to rename it to Invoice_0355676.pdf .
It's all doable but I was wondering if I could pass the correct filename to the printer driver, possibly using tokens. Only thing is, I have no idea how to do that. Can anyone help?