You can easily do this by making a new script in the story editor.
Here's a template.
You can find the list of animation names in Standard Character Animations
and in _Global_CharacterAnimations inside story editor (make sure to check both places because not all animations can be found in one place).
You can get the animation name from the second string which is "knockdown_loop". As for the number I think it is for telling if it's a looping animation or not (1 for loop, 0 for not).
The animation name for dancing loop is for some reason "Dance_02_Loop" when the actual animation is called "Loop_Dance_01".
Also don't use incapacitated for your status type as it will override your animation with the "still" animation. Hope this help!