Moving multiple units via triggers problem

I think i have to use something called unit arrays and i am not sure how to use them.

Basically i create a unit, make it move towards a point via an ability.
The problem is when i use the ability again, the movement works only on the new unit, the old unit stops moving towards its destination. The periodic movement trigger works only on the latest created unit, I need it to work on individual created units so it doesnt cause problems when i use the skill multiple times to create multiple units or when 2 heros use the same triggered skill.

How do i solve this problem??

just have 2 triggers, one to spawn the units and one to move them.
wait a minute for me to make code