programming a ballyhoo

By ballyhoo, do you mean a figure 8 or just a pan back and forth across stage?  The latter can be done as an effect with just two steps: the end positions. 

To do a traditional figure-8-on-its-side ballyhoo, say on a backdrop, set the dead center position, and call it 0,0 (Pan,Tilt).  Moving down and to the right, the next position is +25,-25.  All the way right is +50,0.  Top right is +25, +25.  Crossing center at 0,0.  Lower left to -25, -25.  Extreme left -50,0.  Top left at -25,+25. 

So, for one light:

Step#: PanPos, TiltPos

1: 0,0

2: +25,-25

3: +50,0

4: +25, +25

5: 0,0

6: -25, -25

7: -50,0

8: -25,+25

back to step one for center 0,0. 

The 25 and 50 numbers are merely offsets, and may need to be altered to stretch or squeeze the bally to fit the space desired.  For additional lights, start them at a different step and/or reverse the pluses and minuses.  Once the positions are established (and recorded as palettes/focus points), it takes a great deal of massaging of the in/dwell/out times to smooth out the movement.  You want the light to just almost get to where it's supposed to go before it receives a new instruction to go to the next location.  Additional, intermediate steps would make for smoother movements, but much more calculations.

I hope this makes sense.  I've only done it once, on an Expression with six outdoor searchlights on the side of a building for New Year's Eve of course.  This was in 1993, before the term Effects Engine® existed.  I (usually) don't miss the old days.

Thanks for a nice, clear description.  THis might work for us.