Auto Insert of OCR Symbol on every page of a number of PDF files

[JTofBNY]

I need to accomplish the following:
1) Automatically convert some XLS, DOC, and TXT files to PDF.
2) Automatically modify a number of PDF files (combo of originally PDFs + some files converted to PDF), adding an OCR symbol on every page of every PDF at a specific location on the page.

I am not familiar with VB so if anyone could provide me with specific code or direct me to specific links, I'll greatly appreciate it. Thx!