my $testString = "          01008008 000000DF 00800000";
my $mask       =           "42000000 00000020 00000000";

for ($testString, $mask) {
    s/\s+//g;
    $_ = pack("H*", $_);  # convert from hex to (binary) bitstring
}

# bitwise string AND
my $maskResult = $testString & $mask;

# ----- visualise what's going on (functionally not required) -----
for my $bits ($testString, $mask, '', $maskResult) {
    if ($bits) {
        print unpack("B*", $bits), "\n";
    } else {
        print "-" x 96, "\n";
    }
} # ---------------------------------------------------------------

# check for any non-zero bytes
$maskResult =~ tr/\0//d;

printf "There were %s matching bits.\n", length($maskResult) ? "some":"no";