Hi,
you need to include windows.h, the definition is into d3d9.h

ENABLE_RENDER material flag lets you modify the render of each visible entity which has the material assigned.

(untested code)
Code:
#define skFloatArray     skill20

...

function evnMtl00 () {
	if (mtl->d3deffect == NULL) // no effect loaded?
		return 1; // do not render
	if (me == NULL) // not an actual entity?
		return 0; // render as it is
	LPD3DXEFFECT _fx = mtl->d3deffect;
	// fill a float array, or retrieve a pointer to an array from the entity skill or whatever
	float *_fArray = (float*)my->skFloatArray;
	_fx->SetVector("myFloats", _fArray);
	return 0;
}

MATERIAL *mtl00 = {
	event = evnMtl00;
	flags = ENABLE_RENDER;
}


This is only needed when each entity has its own values for the same variables.