Force release of left click of the mouse button to allow drag/drop object to return to start if it intersects with another object.

Hello hive mind!

I desperately need your help.
I'm creating a mini maze game using the drag/drop function in Storyline.
If the object being dragged around the maze intersects with any of the walls it gets returned to its start point. This all works fine.
The issue I'm having is that if the user keeps hold of the object by not releasing the left mouse button, then the object sporadically jumps around the screen and can appear through walls.
Is there a way to force the release of the left click of the mouse, and therefore release the object to return to its start point?
I effectively need to force the end of the drag/drop interaction the moment the object intersects with any of the wall objects. Is there any way to do this?

Thanks in advance! :)

<< I've attached the storyline file. Currently it's not much of a maze, as there's only one way to exit on each slide, and it leads you back around to the start again. I'm just building up the basic mechanics before I attempt anything more complicated. Also I just grabbed a sprite off the internet to use as character. Has no bearing on final games theming. >>