You really don't have control over the right click menu, same as on the desktop. Is the paste option even there in their right click menu? Are they in an active field before right clicking?
If you hide menus for the file completely, then the right click menu also goes away.
I would suggest you disable all the menus, and develop your own top menu bar with only the actions that you need.
Thanks, this solves my issue.
To answer your questions however, if you "right click" there is no menu or options displayed at all, as if the right click is disconnected. Yes, the person is in an active field at the tme. Using a custom menu appears to be the way to go.