Unwanted substitution of brackets in filenames when printing from Microsoft Word

When printing Word files (auto-save enabled) all brackets in the filename are substituted by underscores. This does not happen when printing from any other windows application. Is this desired behavior? If so why?

How to configure PDFCreator not to replace brackets? We propose using PDFCreator in an automated Word process, which needs the pdf to have the exact name of the word file (including brackets!).