Please try:::::
given:: echo $ADMIN_IPS 8.8.10.1,8.8.10.2,8.8.10.3
and Input file /tmp/myvar given with contents as below::::
-A INPUT -i @PUBLIC_INTERFACE@ -p tcp -m tcp --dport 80 -d @PUBLIC_IP@ --syn -j ACCEPT
-A INPUT -i @PUBLIC_INTERFACE@ -p tcp -m tcp --dport 22 -d @PUBLIC_IP@ -s @ADMIN_IPS@ --syn -j ACCEPT
-A INPUT -i @PUBLIC_INTERFACE@ -p tcp -m tcp --dport 443 -d @PUBLIC_IP@ --syn -j ACCEPT
for i in $(echo $ADMIN_IPS |tr ',' '\n'); do while read j; do echo "$j"|sed 's/@PUBLIC_INTERFACE@/eth0/'|sed 's/@PUBLIC_IP@/1.1.1.1/'|sed "s/@ADMIN_IPS@/$i/";done < /tmp/myvar ; done|sort|uniq Try and let us know.