$STRING =~ tr/a-mN-ZA-Mn-z0-9.&@=/H-Mn-z0-9.&@=a-mN-ZA-G/;

    $STRING =~ s/=/.3d/g;
    $STRING =~ s/&/.26/g;
    $STRING =~ s/@/.40/g;
    $STRING =~ s/\\/.5c/g;
    $STRING =~ s/\s/.20/g;
    $STRING =~ s/%/.25/g;
    $STRING =~ s/\//.2f/g;
    $STRING =~ s/#/.23/g;
    $STRING =~ s/"/.22/g;
    $STRING =~ s/'/.27/g;
    $STRING =~ s/\+/.2b/g;
    $STRING =~ s/\|/.7c/g;
    $STRING =~ s/\?/.3f/g;

    return $STRING;