How can i make it? (something like 'Feather effect')

Hi.

I get some object to other design company.

There is AI file in URL(illustrator CS3 version file)

http://www1.datafilehost.com/d/f873f882

it's looks like 'Feather effect'. but it's not.

it's not possible to copy to below Script code.

Sel[i].duplicate(newGroup, ElementPlacement.PLACEATEND);

So i started wonder about it.

How can i make this object?

and, How can i copy this object to script code?

Thanks you.