open PROG, "|program" or die "Can't open output pipe to 'program'";
print PROG function();
close PROG;

##</code><code>##

my $input = "first line\nsecond line";
open TEMP, '>' "temp$$";
print TEMP $input;
close TEMP;
my $ouput = `type temp$$|\\vim\\vim63\\xxd.exe`;
print $output;
unlink "temp$$";
# (tested)