This can be done in any mode -- a regular game of Scrabble would probably be the easiest. You must create a 9+ letter word, which means you need to build off of at least two existing tiles. Using the same method as "A column of 7" -- set yourself up with an existing "ER" or "ERS" -- both which are valid words. Once you've done that, with the help of http://www.wineverygame.com type in the letters "ER" or "ERS" along with your seven tiles, and eventually it will return a nine letter word for you. Make sure you have plenty of space open before the word you're building onto. If your letters aren't ideal for creating big words, trade them in for new letters until you have a good set. (Ideally, keep all of your A, E, N, R, S, T, and blank tiles.) (For the record, my word was "AIRLINERS".)
Another method is to make the word "LING" "RING" or "TING" (all valid words) and go that route, instead of using "ER" or "ERS."