Boulder to Switch, Using boulders to unlock doors. Options

[nijal]

I've spent 2 days trying to figure out how to solve this problem and I still can't solve it.
Basically the equation is: Move away event (boulder) + Switch = unlocked door. There are 5 boulders and 5 switches.
My attempts would include:
1. Having all the switches on parallel
>Control Variables Screen X and Y
That caused the switches to activate without even pushing the boulder on top of each one; all I had to do was push a boulder past each one.
2. Having them on Same as character
This lead to them acting pretty oddly because if I don't shove the boulder really hard, the switch wouldn't activate and the graphic for the switch would be above the boulder.

I'm currently using Switches instead of Variables because the Variable numbers go past 10 when a switch is activated.

And then I just went through random attempts hoping to solve the problem. May someone please tell me how to solve this problem, thank you.