Yes, replace PARTY with RAID_WARNING. Here are all chatIDs: http://www.wowwiki.com/ChatTypeId.

I updated the post above with a version that works. I would like to know if anyone manages to shorten it a little. Instead of using if not (test) then (say) end it should be possible with a simple (test) or (say), but I can not get it to work.

My /follow macro is currently 252 characters and you never know what you might want to add later.