Yes, I know this. But this is not what I mean.
The functionality I was talking about is this: when your current input method is English, but you want to search for some directories or files named in Chinese. In Spotlight you just need to type the Pinyin in English, and the results will show up. The key here is that you don't need to switch to Chinese input method first, then type the Pinyin, then choose the right candidate characters. So the pinyin search reduce 3 steps to 1 step, and it's more productive.
As for the example I provided above, I type wode with English input method in