Shell Programming and Scripting

I need a perl script that needs to start an executable in a different shell so that I can use this to run more commands from my script. This is what I have:

my $USER = "my_user_name";
mu $HOST = "hostname";
my $ssh = 'ssh $USER@'."$HOST";
my $cmd = "cd $EXE_DIR && sudo $EXE $EXE_PARAMETERS";
# To start the executable...
system ("$ssh '$cmd' < temp_pipe 2>&1 &");

# To run commands on this ...
if (some condition)
$cmd = "Enable module 1";
system("$rsh '$cmd'" );
else
$cmd = "Enable module 2";
system("$rsh '$cmd'" )

When I do an rsh, it complains saying the executable hasnt been started. Any suggestions?

Thanks!