Monitoring print jobs and changing what prints??

Hi,
 I have an interesting question, and I can't seem to find anything that helps anywhere.

 I am trying to make a program, that monitors every print job that happens on a computer. If it finds one from a certain program, It shows a Dialog that asks a few questions.... like "What is your name?" and then prints your name on the paper that comes out, but on top of what was sent to the printer. Is this possible? Please help ^_^

Thanks!