cube 1 skill1 = 1; // set this in WED
cube 2 skill1 = 2; // the same...

ENTITY* cube_1; // Entity Pointer
ENTITY* cube_2;

action cube_action()
{
if (my.skill1 == 1) cube_1 = me;
if (my.skill1 == 2) cube_2 = me;
...
}

Now you can access to that two entities with this two Pointers:

cube_1.x = 20;
cube_2.x = -100;
set (cube_1,PASSABLE);

and so on...