How to get a single bone accessible at runtime (Blender->Unity pipeline)?

I have been all over the internet, and through all docs for Blender and Unity - with no luck. Can anyone tell me how to simply add a Bone / Tag / Node to a mesh that can be exported into my .FBX and be accessible to my runtime???

I'm not talking about an animated character with a full rig. I just want to tag a location in a mesh so that I can attach an effect, joint, etc. to it later. I've never seen so much documentation about all aspects of rigging and animating and not found this most humble of tasks covered.

I did everything one can do with Armatures, vertex groups, bone weights, layers, empty objects, parenting and every other kind of thing to try and simply get a node (tag?, bone?) that I do not want rendered, but simply referenced as a transform.

Can someone please help? Thanks!