use Interpolation '%:$$->$' => sub {sprintf '%'.$_[0], $_[1]};

my $x = 41.758;
my $name = "Jenda";
print "Hello $%{'06d'}{$x} or $%{' 10.5f'}{$x}, $%{'20s'}{$name}, and so forth\n";

$x = 1.7;
$name = "Leaveolus";
print "Hello $%{'06d'}{$x} or $%{' 10.5f'}{$x}, $%{'20s'}{$name}, and so forth\n";