I asume you need to auotmate the fx on or off....

To do this, on the mixer channel, find the right Fx, and there is a little green button and a knob on the right. You can either automate the knob to turn off, of the button to switch off.

For instance, i have a kick drum and i want the reverb to be on pattern 1, but not on pattern 2. I set the kick drum to FX channel 1, then open the mixer, select channel one, select reverb in the plug list, then making sure i have patern 1 selected, i right click on the green button and select "edit events". Then i put one line in at the begining of the event editor above the halfway point. Then with the event editor still open, i change the pattern to pattern 2, and then i put a line in at the begining, below the halfway point.

The fx will now switch on and off acording to which pattern you are playing, open this fruity zip file to hear the result - http://www.clubfaction.net/kick.zip