How to redefine Open comand for Writer with xcu file?

I need to intercept native Open… menu entry pressings (which refers to .uno:OpenFromWriter command) and replace it with my own command. I’ve added this command via custom OXT extension. At the moment I can launch this desired substitute command from separate menu entry and disable original .uno:OpenFromWriter with my own xcu like in this example. Is there any example for similar xcu that redefines menu entries?