Winforms mousedown event across multiple controls

Hi, i've got a winforms usercontrol which is pretty much a time scheduler (24x7) in hourly blocks which ive used labels to represent each hour slot.

The labels have multi-stage select on each click (off, low,med,high) which works fine when i click on each one separately, but what im trying to achieve is the following:

Click the mouse on a label, hold it down and drag it across other labels, triggering the mousedown event on them also so i can select multiple timeslots in one click-drag.

Any help appreciated.

thanks.