API / Code for adding text equal to the filename to a PDF Document

Hi there,

I need to add the file name to the top right an existing PDF document (it is a scan of an invoice). I'm using MS Access & VB to process the scan, assign the file name and email the PDF off to the OCR capture service. All I'm short of is the code / API to add the file name to the PDF document that I've created while scanning. CutePDF has the functionality to add the file name to the header of an existing PDF document, but it seems to lack the functionality to do lots of files at once and then save it back as the same file name.

Does anyone of there have experience with this type of thing?

Thanks!