Decode Function in DS

Hi

Any one can help me how to get this logic in BODS

Created the Custom in field as Level1 in The Transforms trying to inert the logic below , The below logic was there in Oracle Source table , target table is SQL.

Can any one help me to fix this logic.

"

DECODE(SUBSTR(PC,1,1),'0','',SUBSTR(PC,1,1)||'000')AS LEVEL1,"