[plt-scheme] Simple scheme idiom?

> Is there a simple scheme idiom to do this?
>
> Given:
>
> '(a (b c (d)) e ((f)) g)
>
> Produce:
>
> [z ([z a] [z ([z b] [z c] [z ([z d])])] [z e] [z ([z ([z f])])] [z g])]

This looks very much like homework.  What problem do you have with being 
able to write this?  This appears to be something that the chapters in 
Part II in HTDP should directly address:

http://htdp.org/2003-09-26/Book/curriculum-Z-H-12.html#node_part_II

Can you give us context as to why you're trying to do the above problem?