Can someone explain to me how to work with Strings and Catalog Data stuff?

I am currently trying to create an ability that will reset the cooldown of the 3 abilities situated on the left of the last row of buttons of the command card of the targeted unit.
In addition to that, the next time the targeted unit will cast any of those 3 abilities, it will cost it 0 energy (instead of 'x' amount). Once it casted an ability, the effect should wear off and everything should cost the same amount as it did before (and cooldowns shouldn't be restored to the value they were at before the ability was casted on the unit: they should stay to 0, except for the "free ability" the targeted unit got to cast).
The ability would allow the targeted unit to cast its ability for free, but this unit would have 6 seconds to do so.

Here is what I have done so far: EffectTarget Ability linked to an ApplyBehavior Effect linked to a Buff Behavior. The Buff Behavior lasts 6 seconds and basically acts as a dummy.
I made a trigger that uses the "Unit Behavior Change" Event ("Unit - Any Unit has Medic - Temporary Restoration (Dummy) change Any"), but I have no idea how to make the triggers...
I know using Strings and Catalog Data is most probably the most efficient and less tedious way of doing this. Can anyone help me understand those?

Thanks.

Any help?

For starters a lot of the fields that catalog triggers list can't actually be changed with the catalog trigger, secondly I'm not sure what the 'behavior change' trigger does or if it does anything (it's a recent addition).
I would make it so the behavior has an Initial Effect defined or whatever that field is called, and make your trigger detect that dummy effect with an Effect Used event, then you use Triggering Effect Unit in the rest of the trigger.