Impale spell inquiry

Hello, thanks for anyone who would help.
I was wondering if I could detect units that are affected by the spell impale and do things to them.
An example scenario:
Caster casts Impale targeting a point (in the ground), then, units affected by the Impale get thier movement speed slowed by 50.

Is this possible? I'm a noob in both Jass and GUI so I could'nt figure this one out, the best thing I did was if the caster is castin on a unit, which is not what I was trying to do. Again thanks for any help or suggestion.

perhaps get units that get the buff from getting hit by impale? unless there is no buff for impale

okay:

should work :P

hey tiku thanks I also thought of that solution but due to my lack of knowledge I failed LOL

Edit: +REP for the effort my friend lol. Thanks, seriously.

lol well i posted a trigger if you need it :P might work might not

Is there an alternative, I cant get this one to work. Thanks for any help.

Dummy cast Thunderclap on the point.

A small thread steal:
Where can I find a tentacle model for impale?

There's a unit that has a tentacle model. Servant of something I think.

Just scroll through the unit models and you'll find it.

No no, not the tentacle of faceless one I need the spike of nerubians impale.

its under the models of: buffs, in the "I" lettering section

Got it:
Abilities\Spells\Undead\Impale\ImpaleHitTarget.mdl

That's not a tentacle, lol. It's a spike.

Hey guys, can you tell me how to code this:
Pick every unit within 1000 range of caster but pick only the ones that has buff
I got stuck on this one, cant determine what code to make. I need to filter the units and only pick out the ones with an impale buff.
Thanks pyro for the help but I want to test if this coding would do it.
Off Topic question: Is it hard to add a buff to a unit? I mean without using dummy casters to cast spells on the targeted unit.