Customizing page numbering

[Adam Schweitzer]

Hi All,
 
We have some documents which need to have pages numbered in the
following way:
n / (n + 1)
where n is the page number.  (IE. on page 33, it needs to say 33/34).
 
Inserting a variable defined as <$curpagenum> gives page n - but I
cannot figure out a way to insert n + 1 (ie. <$curpagenum + 1> does not
give the result I hoped for..)
 
How would I go about doing this?
 
Regards,
Adam Schweitzer
Orenda Aerospace