use IPC::Open2;

my $infile = shift;
open (INFILE, "<$infile");
my $output;
my $input;
{
    local $/ = undef;
    $input = <INFILE>;
}

my $pid = open2(*README, *WRITEME, 'progam.exe');
print WRITEME "$input";

{
    local $/ = undef;
    $output = <README>;
}

close(README);
close(WRITEME);
waitpid($pid, 0);

print "$output";