I actually don't know how to do it in Dota 2. I would tell you to use a $attachment line in your QC file, but Dota doesn't deal with QCs. Either Valve does the particle effects for you, or there is another way to do it. But I don't really know, so I'm sorry to say I can't help here!

Haha, it's ok Helljumper, thanks a lot anyway. Your tutorials have already helped me a lot :)