Perhaps DBD::Excel would be of some use to you for your first question.

I'm not sure otherwise, there's probably a special character to get around it.

You might want to make an Excel file, do what you're saying (put a list of things in a cell), then export to text and see what it loos like. It may be an XLS specific "XML".

.txt isn't really a "format", so to speak. You might want the "format" Perl command if that's what you mean. Not sure for .doc either because you'd really need a template.

HTH