this all depends a little on your sketch.

There is no easy "define" for this, but what you could do is define your own function to set a pixel.

For example, say you're using FastLED, where you can set a pixel with:

leds = color;

Now you could create your own function, something like this:

void setLED(int LedNo, CRGB color)
{
  if( (LedNo<>10) && (LedNo<>11) )
  {
    leds=color;
  }
  else
  {
    leds=CRGB::Black;
  }
}

This will set the LED color only if it is not #10 or #11.
If it is #10 or #11, it will set it to black (off).

Setting a LED color, so wherever you used to call "leds=color", you now do this:

setLED(lednumber, color);

Hope this helps.

but led 10 and 11 should not light up

how can i define it