Append iptables rule to existing config

Hi all,

A while ago i’ve asked this question. I use a template since and it works fine for me. I’m running 21 VM’s, and i need to add a firewall rule to 7 of them.
Now i’m back to my old question, how to add --set to -m recent. Is it possible to do? I prefer to keep one basic template for all servers. Or is it somehow possible to append iptables rules via another template?