[kevin_p]

Something similar is even built into many pinyin IMEs. To take the same example OP used, Microsoft Pinyin (the default Chinese input method on Windows computers) will let you input 榎 by typing umuxia.

(Explanation: U puts it into component mode, then mu = 木 and xia = 夏)

It's a bit more finicky than OP's version though because the order is important, uxiamu won't give you any useful results.