Is it possible to create a footer in Word (2007) with 3 fields that are dynamic?



What I am trying to do is have a line that says:

Printed by "username" on "date"
Document is valid for 3 days, please dstroy after "date +3".

I have no experience in this area so please be kind and explain what code needs to go where.
Just to clarify a bit further, I already have a date and a username field that display the correct name and date, but those fields don't automatically update to the current values when someone else opens the document. They'll have to do a print preview first which appears to be one step too many for most to remember! The "date +3" field I can't get to work in Word.


thank you for your help,
Walter