I'm afraid the image still doesn't make much sense.
What you are trying to do it seems is select a specific instance, according to a user input.
In Construct 2 that's called picking, and is a basic of how events work.
You can do it by comparing the value of an instance variable, and making sure that each instance of the object type has a unique value.
Construct 2 is actually it's own sort of programming language I would dare to argue in opposition to the previous commenter.
But still it has its own ways, and needs a bit of habit to get into.
In the end, I feel like you are asking the wrong question because of your habit of other programming languages.
What is it exactly you are trying to achieve in the first place (the general mechanic, not the "construct an object with variable").
If you're trying to get some selected object to move to a certain position according to a user input, here is an example capx that could do the work.
In this example each "Object" instance is create with a unique "ID" instance variable value.
From there, when the user inputs a number from 0 to 10 (because on start of layout only 10 more instances are created) and click the button, only the instance with the entered ID is selected and its pathfinding behavior set to move it to the EndGoal.