If you had actually looked just a little harder you would of found this.
You will need D2Hackit to work the module which can be found also on mewgood.
Load the module by using ".load dupe", than access the instructions by typing ".dupe help" this will tell you how to use the module. This worked for most versions of 1.09, If it does not work for you, than you can browse mewgood a little more, you are bound to find one that does.
Same concept goes for Yay, it was a revamped Dupe module.
My assistance to you stops here, I will no longer do your searching for you.
EDIT: Was nice and added D2Hackit complete with source.
Removed fake hacks. ~x42bn6