mouse-drag-secondary-pasting
mouse-drag-secondary-pasting is an interactive compiled Lisp function in `mouse-copy.el
'.
(mouse-drag-secondary-pasting START-EVENT)
Drag out a secondary selection, then paste it at the current point.
To test this function, evaluate:
(global-set-key [M-down-mouse-1] 'mouse-drag-secondary-pasting)
put the point at one place, then click and drag over some other region.