use strict;
my (@keywords, %keyword)=qw/foo bar 12345 abcd/;
my ($string, %result) = "foobarfoo1234523423412345abcdefsadfabc";

##</code><code>##

@keyword{@keywords} =  map {qr/\Q$_\E/} @keywords;


##</code><code>##

$result{$_} = () = $string =~ $keyword{$_}
    for (keys %keyword);

##</code><code>##

my @regexen = map {
    qr/(?:\Q$_\E(?{$result{$_}++}))/
} @keywords;

my $re = do {
    local $" = '|';
    qr/@regexen/;
};

##</code><code>##

$string =~ /$re/g;
print "$_: $result{$_}\n" for @keywords;