[gm9]

Yes that works as you said in the OP, except you'd put it in a custom UI folder as Aditu explained. Just make sure to name the window with the cure buttons Player (in the XML) so they light up.

edit: maybe to add some more detail just in case: create one window with a file name of eq2ui_mainhud_player.xml, the other one you can give whatever file name you want and you <include> that second filename in eq2ui_custom.xml. All those files go into your custom UI folder. Add some code OnShow of the first window to show_window the second window and you're done.