# ugly, but works:
my $failmsg = "\\*E";
if (/$failmsg/) { ... }

# nicer, since you don't have to do the escaping yourself
$failmsg = '*E';
if (/\Q$failmsg\E/) { ... } 

# if you want to quote regular expressions, do this:
$failmsg = qr{\*E};
if ($_ =~ $failmsg) { ... }