for my $line (@lines) {
	# break the line into an array of words minus exclusions
	my @words = grep{ !(1+index($excluded,$_)); } $line =~ m/\b\w+\b/g

	# Word breaks to avoid partial word matches
	local $local $"='\b|\b';  #"

	# replace each line with a multi-matching compiled regex
	$line = qr"\b@a\b"oi;
}