You could always build the format dynamically and then eval it</slightly-evil> :)

I also think Perl6::Form has support for specifying a width numerically rather than by literal picture, but I'm not recalling how to do it offhand.

Update: Aaah, search for "Imperative field width".

use strict;
use Perl6::Form;

my( $name, $age ) = ( "Fred", 23 );

print join( " "x9, 0..7 ), "\n", "0123456789"x7, "012\n";
print form
  "{<{50}<}|{|||} ",
    $name,     $age;

exit 0;
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