Michael,
That driver does not exist as much as i can tell.
But, I can help you! Attached is a zip files with some routines i wrote for the 86100. Now, I wouldn't call them instrument drivers since they do not conform to NI's definition. I just can't see spending all the time developing code I wont use (in a production enviroment, time is everything). But, there is a good amount here.
I used the scope for eye pattern measurments in the fiber optic industry, so some of this may not be of use to you. But there are vi's to call and query the different calibrations, apply the cal rules stated in the Agilents programming guide (as to when a cal should be performed), loading a mask, setting the mask margin percent, starting and stopping the mask measurments, quer
ying various registers, initialize (how I need it done anyway) and or reset, calling the autoscale command, returning measurements.
Here is a link to Agilent's help file for programming (might be more up to date than the printed manual and is searchable).
http://www.tm.agilent.com/classes/MasterServlet?view=manual&man-ItemID=1000000597&language=eng&locale=US
Oh BTW, there is at least 1 bug with the firmware downloadable from Agilent (ver 2.0). The command to turn on the mask would not always work. If you brought up the dialog (on the 86100 screen) to turn on mask, it would sometimes be disabled (greyed) and I think the fix was to cycle quickmeasure (hit the button twice) (not sure though) to re-enable it. If you stick with ver 1.2, you wont have this problem. I ended up going back to 1.2 and notifying Agilent.
This should get you going.
Jared