#!/usr/bin/env perl
use strict;
use warnings;
use feature 'say';

my $regex = build_regex( 2, 4, 3 );
say "Regex: $regex";

my $string = "xxxx yy zzzzz xxxx qqq xxxx yy zzzzz xxxx qqq";
my @match = $string =~ /$regex/g;
say "Match: @match";

sub build_regex {
    my ( $first, @others ) = @_;
    my $regex = qr{\b(\w{$first})\b};
    $regex   .= qr{.+?\b(\w{$_})\b} for @others;
    return $regex;
}

__END__
Regex: (?^:\b(\w{2})\b)(?^:.+?\b(\w{4})\b)(?^:.+?\b(\w{3})\b)
Match: yy xxxx qqq yy xxxx qqq