...

my $PATH = "!please don't show this!";

my $command = 'echo test.sh';
my $args    = "\\\$PATH is a name";     # try: "\$PATH is a name";

print "args: ",  $args, "\n";
print "dummy: ", $PATH,"\n";

my $output = qx{ $command $args };      # use qx for backticks!
print "\ncommand line echo: ", $output, "\n";
...