Hi Bjones,
(a) Set the original print area something like this =Sheet1!$A$1:$A$21 by selecting 'Page Layout' / 'Print Area' / 'Set Print Area'
(b) Go to 'Formulas' / 'Name Manager' and then use a formula like this: =OFFSET(Sheet1!$A$1,0,0,Sheet1!$B$1,1)
Make sure that you change "Sheet1" to whatever your sheet name is.
The reference to cell B1 is the height or the number of rows to print.
If you would like to review the OFFSET function's parameters I am sure that Chandoo has some excellent blog posts about this!
Excel should now print only the required number of values
Cheers,
Kevin