if you store it like this:
$String = "\$string = \"The IP address, $_SERVER[REMOTE_ADDR], you are using has been blacklisted due to suspicious activity\";";
Then, you could call eval() on it when you pull it out. try something like this:
eval("\$string = \"The IP address, $_SERVER[REMOTE_ADDR], you are using has been blacklisted due to suspicious activity\";");
echo $string;