slowing down creeps

[shadowsun]

I have made a channaling spell and it takes like 5 sec to cast but by the time it is fin all the creeps have run or my hero is dead. can someone tell me how to slow all the creeps attack and move speed in a area so they still have a chance to run but might be to slow.

eg. get my dummy to cast slow on all creeps.

 

[cjp2008]

Create and order an invisible dummy unit to cast thunderclap?

 

[ap0calypse]

Can't you use a trigger for that? "Set movement speed"
Just pick all creeps in the area you want and slow their MS, after the spell is cast, change their MS back to normal.