I can find it on a Mac. It's at this path:
<home> > Library > Preferences > Adobe InDesign > Version [your number] > en_US > Word Import Presets (In later versions of the Mac OS X, hold down the Option key while selecting Go > Library to open the Home Library folder.)
The file has the extension .smp
If you're on Windows, maybe someone can discover where the Preferences are found on your OS.