Is there a possibility to parametrize format-strings.
E.g. I want to provide a function [print_string], that,
given an integer [i], right-aligns a string as if it was 
of length [i]. But following code is obviously not
possible:

 let print_string i s = Format.printf "%%is\n" i s;;

Since "%%" is a `normal' %. But since I do not know the
needed length in advance I can not write something like

 let print_string i s = Format.printf "%10s\n" s;;

Any suggestions?

cheers

christian