[ms office - 2007] Make available paper sizes printer-agnostic?

[pete]

Word 2007 appears to list paper size choices based upon the default printer. If my default is an A4 printer, it will only list sizes up to and including A4. If I change my default to an A3 printer, it will offer sizes up to and including A3.

 

I understand why it does it - it reduces the scope for foot-shooting.

 

Is there a way to override (without creating a custom size) it so an end-user has the option of an A3 document at times when they only have an A4 printer available?