try this...
sed 's/RETR..RETR\(.*\) \(.*\)/get \2/g' FILENAME |sed 's/get \/...*...\//get /g' | sed 's/STOR..STOR\(.*\) \(.*\)/put \2 \1/g' |sed 's/RNTO..RNTO\(.*\) \(.*\)/rename \2 \1/g' | sed 's/RNFR..RNFR\(.*\) \(.*\)/rename \2 \1/g'| sed 's/rename.*.\"$/&Makethisgoaway/g' | sed 's/put.*.\"$/&Makethisgoaway/g' | sed 's/.Makethisgoaway//g'
sorry for all the mickey mouse things I've thrown in to work around the " marks.