I am not sure what you mean by "netgroup". If you mean NIS-groups they are stored in /etc/netgroup on AIX and i suppose on other systems too - if you could tell us your OS we could probably give better/less generalised advice.
How about something like:
#! /bin/ksh
typeset fList="/path/to/list" # list of server names to process
typeset fWork=/my/work/directory"
typeset chServer=""
while read chServer ; do
if ! scp "root@${chServer}":/etc/netgroup "${fWork}/netgroup.${chServer}" ; then
print -u2 - "Error processing Server $chServer"
else
cat "${fWork}/netgroup.${chServer}" >> "${fWork}/complete.list
fi
done < "$fList"
exit 0
There sure is much to be done on this script skeleton, but it should work as a starting point.