Alright, I have this code now:
Code:

---

material mat_ffp_multitex
{	
	event = mtl_terraintex_init;
	skin1 = blendmap1; //Blendmap for  texture 2
	skin2 = blendmap2; //Blendmap for  texture 3
	effect
	"
	TEXTURE entSkin1;
	TEXTURE entSkin2;
	TEXTURE entSkin3;

	TEXTURE mtlSkin1;
	TEXTURE mtlSkin2;


	matrix matMtl;

	technique ffp_terrain_tex
	{
		pass P0
		//////////////////////////////////////////////////////
		//// Lets lay the first TEXTURE down.  no alpha work
		//// This will tile across the entire HMP
		//////////////////////////////////////////////////////
		{
			
			alphablendenable=false;
			alphatestenable=false;
			
			zenable=true;
			zwriteenable=true;
			
			////////////////////////////////////////
			// Stage 0
			///////////////////////////////////////

			TEXTURE[0] = <entSkin1>;	

			magFilter[0]=linear;
			minFilter[0]=linear;
			mipFilter[0]=linear;
			
			TEXTURETransformFlags[0] = Count2;
			TEXTURETransform[0] = <matMtl>;
			texcoordindex[0]=0;

			ColorArg1[0] = TEXTURE; 
			ColorOp[0] = SELECTARG1;
			
			alphaop[0]=disable;
			
			//////////////////////////////////////
			//stage 1
			//////////////////////////////////////

			colorop[1]=disable;
			alphaop[1]=disable;
			
		}

		pass P1
		//////////////////////////////////////////////////////
		//// Now we blend another TEXTURE using an alphamap
		//// This TEXTURE will be blended
		//////////////////////////////////////////////////////
		{
			
			//////////////////////////////////////
			// Stage 0 - Setup the alphamap
			//////////////////////////////////////            		

			// We need to enable alphablending 
			
			alphablendenable=true;
			srcblend=srcalpha;
			destblend=invsrcalpha;
			
			// AlphaTestEnable uses the AlphaRef and AlphaFunc to 
			// determine which pixels get drawn.
			// In this case, anything greater that 0 will be drawn.
			alphatestenable=true;
			alpharef=0x00000000;      	//Reference Value
			alphafunc=Greater;  	  	//Comparison Function
				
			TEXTURE[0] = <mtlSkin1>;

			magFilter[0]=linear;
			minFilter[0]=linear;
			mipFilter[0]=linear;
			
			//
			// We don't want the alphamap to tile
			//
			TEXTURETransformFlags[0] = disable;
			
			texcoordindex[0]=0;	
			
			COLORARG1[0] = CURRENT; 
			ColorOp[0] = SELECTARG1;
			ALPHAARG1[0] = TEXTURE | ALPHAREPLICATE;
			alphaop[0]=selectarg1;

			//////////////////////////////////////////////
			// Stage 1 -- This is the TEXTURE to splat
			//////////////////////////////////////////////

			TEXTURE[1] = <entSkin2>;
			

			// Zenable is supposed to default to true.  
			// This enables depth testing to determine what pixels 
			// are visible to the viewer
			
			zenable=true;
			zwriteenable=true;

			magFilter[1]=linear;
			minFilter[1]=linear;
			mipFilter[1]=linear;
			
			
			TEXTURETransformFlags[1] = Count2;
			TEXTURETransform[1] = <matMtl>;
			texcoordindex[1]=1;

			COLORARG1[1] = TEXTURE; 
			ColorOp[1] = modulate;
			ALPHAARG1[1] = CURRENT | ALPHAREPLICATE;
			alphaop[1]=disable;
			
			///////////////////////////////////////////////
			// Stage 2
			///////////////////////////////////////////////
			colorop[2]=disable;
			alphaop[2]=disable;
			
			
		}

		pass P2
		{
			
			////////////////////////////////////////
			// Stage 0
			////////////////////////////////////////

			alphablendenable=true;
			srcblend=srcalpha;
			destblend=invsrcalpha;
			
			alphatestenable=true;
			alpharef=0x00000000;      
			alphafunc=Greater;  	 
			
			TEXTURE[0] = <mtlSkin2>;
			
			magFilter[0]=linear;
			minFilter[0]=linear;
			mipFilter[0]=linear;
			
			
			TEXTURETransformFlags[0] = disable;
			
			texcoordindex[0]=1;
			
			COLORARG1[0] = CURRENT; 
			ColorOp[0] = selectarg1;
			ALPHAARG1[0] = TEXTURE | ALPHAREPLICATE;
			alphaop[0]=selectarg1;

			/////////////////////////////////////////
			// Stage 1
			/////////////////////////////////////////
			TEXTURE[1] = <entSkin3>;

			zenable=true;
			zwriteenable=true;
			
			magFilter[1]=linear;
			minFilter[1]=linear;
			mipFilter[1]=linear;
			
			
			TEXTURETransformFlags[1] = Count2;
			TEXTURETransform[1] = <matMtl>;
			texcoordindex[1]=0;

			COLORARG1[1] = TEXTURE; 
			ColorOp[1] = modulate;
			ALPHAARG1[1] = CURRENT | ALPHAREPLICATE;
			alphaop[1]=disable;
			
			////////////////////////////////////////
			// Stage 2
			////////////////////////////////////////
			colorop[2]=disable;
			alphaop[2]=disable;

		} // End of Pass P2

	} // End of Technique
	";
}

---

three textures, they all blend perfectly. Now a last question: Is it possible to use dynamic lights on them? This is really important for the game.

The terrains reacts on fog but not dynamic light.