Hi Gerardo,

The MEL command seems to be:

toggleButton_Press("HairFromGuides", "HairFromGuides1.rememberRootPositions", {"Remember Root Positions", "Remember Root Positions"}, {"distribution","randomSeed","uniformRandomness","distributionMultiplier","distributionChannel","topologyBasedOrientation","renderCount","useGuideProximity","guideProximityDistance","useGuideFaces","guideFacesIterationCount"});

Which takes quite a few arguments. Maybe you can put this inside a for loop after you find all the nodes of type HairFromGuides in the scene. 

Jeordanis Figuereo (Product Designer. EPHERE Inc.)