Where can I find the syntax and semantics for expressions available
for use in page headers/footers?

The Excel 2003 built in "Help" says that you can use the predefined
buttons or type a few "&[{functionname}]" functions in the
header or footer. (The functions are, &[Page], &[Pages], &[Date]
and a few more.),

However, it doesn't mention that you can use constructs such as
&[Page]-2&
to get 2 less than the page number.

Where can I find the complete syntax and semantics for what is
permitted?

Thank you.