OK...found it. It's in lsbox. If you're using the anti-depressants color scheme, look in:

C:\LiteStep\themes\Skylight\images\antidepressants\box\bar.box

Edit that file where it says:

*WharfModule 159 9 280 30 $LitestepDir$\systray2.dll

I *guess* you have to give the beginning and end X, Y coordinates...that's why there are 4 numbers.