Printing on specific locations on paper

I have some pre-printed A4 papers and I want to print some data on them on specific locations on the paper (think of it as a form with boxes which must be completed). I 've tried to do it with html and css and i 've managed to display the data correctly on the printed paper with my configuration (specific margins, printer, etc).

My hesitation is if the browser, the printer, the printer driver (or some other parameter) affect the way the data are printed in a way that I won't get the right result.

Is it feasible to use html and css for accurate printing? If the answer is yes how would you do it? (My approach is using relative positioned divs for each page with absolute positioned divs for every box of the form) If the answer is no what would 开发者_JAVA技巧propose alternatively? (maybe html and use of table tags? something else completely different?)

I would do it in PDF or Flash. Very similar to the way www.stamps.com do when you need to print stamps.
Reason for those two technologies is they are really cross platform and give same results on all systems.