my $code = sprintf <<'EOC', $var1, $var2;
sub doSomething {
   my( $arg1, $arg2 ) = @_;
   my $result;
   ...
   my $var = 2 * %d * %d;
   ...
   return $result;
}

##</code><code>##

my $code = sprintf <<'EOD', $a, <<EOD2;
my $var = %d;
%s
my $y = 123455;
EOD
my \$x x= 1000 * $.;
EOD2

print $code;
my $var = 0;
my $x x= 1000 * 18;
my $y = 123455;