I did not get it accurately i think...
Creating xml without registering in somewhere won't work. You don't have to create a xml file.

If you wanna use something that works(not well), use InteractiveObjectEx entity. Reload scripts when you change its model.
And in its properties, check "usable" box(if you want, you can add use message of course). By the way, to see which animations it's using, you should go to "Mannequin editor->interact-><default>".
(Don't forget that, it must not be used for a release game. It has got many bugs...)

https://www.youtube.com/watch?v=mf1bSEWs0TI