use second sanguinolulu to expand extruders

Hi Everyone,
This is my first posting.
I have successfully built a Rostock with traxxas ends and Sanguinolulu 1.3a (with mod for fan control.)
I am using Kisslicer, Repetier host and both Marlin and repetier firmware.
My question is ....can I easily address 2 sanguinolulus using 2 extra drivers ( stepstick) on the second board.
I could not find anyone doing this on the forums.
My first thoughts were to piggy back initially one extra drive board for dual extruder and find a spare i/o to enable it as i had with the fan mod.
Then I thougtht Richraps triple blend head was where I would want to go (eventually). So I thought 2 sanguinolulus was a simple solution with lots of expansion.
But here is the crunch..I don't know how to program this, so need help.
Any suggestions welcome.