Assuming you already know how to create and upload mod on steam (You can ask if not).
1. Go to the Take No Prisoners steam workshop mod folder.
2. Copy the file template_enemy.lua or any enemy file from TakeNoPrisoners_CONTENT folder and put it on client folder of your mod with a custom name.
3. Mutatis mutandis.
4. Use these functions ...

TNP_spawners.add_field_spawner(fieldSpawner,3)
TNP_spawners.add_building_spawner(buildingSpawner,3)

(debug)
TNP_spawners.add_context_field_spawners("myEnemy - Field",fieldSpawner)
TNP_spawners.add_context_building_spawners("myEnemy - Building",buildingSpawner)

... to register the spawners of your addon, so the TakeNoPrisoners mod will spawn automatically your custom hostile npc.

your addon must obviously require TakeNoPrisoners mod and the PZNS_framework mod.