Sounds like you probably could rip it out and replace it with something like Template Toolkit or the like. Just replace your placeholders (I'd call them that before "anchors", which usually brings to mind ^ and \z and related regexen friends in a Perl context) with [% REINSERT.12 %] and populate the template variables accordingly ($template_vars->{'REINSERT'} = \@reinsert_array;). Then you get to let someone else worry about the efficiency bits.