Hi Hyun,
I am not sure if you created the blog but I was in the need of a sample for this. I was able to get mine working .. I am currently working on SP09 and I am also able to see the CTE from the plan viz perspective when SAP does the break down of steps and how long it takes to execute.
here is my example in case anyone needs it:
with y as (
select col1, col2 ,coln
from someTblOrView
)
select * from y;
hope this is helpful for others as well.