How to instantiate in Hierachy

So how do I instantiate an object at a set position the the Hierarchy? Currently when I instantiate an object using..

Code (csharp):

1.  
2. directoryButton[x]=Instantiate (firstButtonObject);
3.  

..it appears in the root. (even if the original obeject was a child object of another in the Hierarchy pane. I want the object to be a child of another object once created.

Any ideas? I coulnt find anything in the docs.
Cheers

 

for parenting use

Code (csharp):

1. transform.parent

which would be the transform of the object you want to parent it to..

http://unity3d.com/support/documentation/ScriptReference/Transform-parent.html