use strict;
use warnings;

my $msg = "the quick brown fox jumps over the lazy dog";
my $text = "fox";
my @words = ( );

if ($msg =~ /$text \s (((\w+) \s?)+)/x) {
    @words = split(/\s+/, $1);
    # @words now contains the list you want...
    printf "Words: %s\n", join(',', @words);
}

__END__
[Results]  Words: jumps,over,the,lazy,dog