nvFX - how to directly override shader in pass

nvFX_code

nvFX::IShader *shdPtr = fx_EffectMaterial->findShader( "SomeShader2" );
    
if (shdPtr)
{
  // lets override current shader in the first pass of specified technique
	fx_pass = fx_TechMaterial->getPass(0);
	
	fx_pass->invalidate();
	
	// Nnnn 1 - directly override shaders

	nvFX::IPassEx *fx_passEx = fx_pass->getExInterface();
	nvFX::IPassState *fx_state = fx_passEx->findState("CustomState");
	if (fx_state)
	{
		nvFX::IPassStateEx *fx_stateEx = fx_state->getExInterface();
		fx_stateEx->setShaders( nvFX::IPassState::TFragmentShader, &shdPtr, 1 );
	}
	
	// validate
	fx_pass->validate();
}

nvFX_shader

namespace States < programTarget="CustomState"; >
{

	GLSLShader global SomeShader1
	{
		...
	}

	GLSLShader global SomeShader2
	{
		...
	}
}

Technique t0
{
	Pass p0
	{
		RasterizationState = rasterStateFill;
		
    VertexProgram = All::VS;
    FragmentProgram = All::PS;
		FragmentProgram<"CustomState"> = SomeShader1;
	}
}