A custom spell question

I want to make a spell that when clicked, expells some mana and cool down that when activated a trigger sets off. I based the spell off of the item ability for heal potion, set healing to 0 and set it so everything works.
What I can't figure out is how to detect it in triggers. I thought that is what the order=____ line in functions does but I'm not sure. Did I screw up my trigger and thats it, is there another way to do it, or is it impossible?
I was using
Event- Unit (I just chose a unit for testing) does action with no target
Condition- Issued order is equal to "Alchemy" (Name of spell)
Action- Create potion in triggering heroes slot 1


On a side note is Inner Fire impossible to turn into a hero ability or did I just mess up something?

You could just modify an existing spell, like I dunno, Summon Water Elemental should work. Just replace the icon and text, then remove the summoned unit immediately and create the item in your inventory. You could probably also do it with Divine Shield, and just set the duration to nil.

im not sure what both of u are talking bout, but there is no need to remove the WE if it has a duration of 0 secs
together with event unit is summoned by player u can do lots of stuff

you cannot ADD orders, they are hard coded. what does this mean? you cant detect a Item-to-hero moded spell because... items dont have orders =(

Use (creep) unit spell or an unused hero spell. =P
(just be careful not all spells have orders, ie. immolation, windwalk, divine shield, some others)

I was just wondering if I could do with custom spell. That is fine, thanks everyone for their input. I guess I will just use an unused spell.