SQL Date Conversion Statement Error

I have a field that is a decimal date (YYYYMMDD). I need to find all
records that are a year or less old. Since date are so easy, I am
trying to do:

WHERE DATE(SUBSTR(CHAR(A.CPADDT),1,4) CONCAT '-' CONCAT
SUBSTR(CHAR(A.CPADDT),5,2) CONCAT '-' CONCAT
SUBSTR(CHAR(A.CPADDT),7,2)) > CURRENT_DATE - 1 YEAR

This works great in the SELECT portion. When I put it in the WHERE
section I get "Selection error involving field *N."

I am really started to hate decimal dates just as much as our other
developer hates date fields.

Any ideas of what I am doing wrong?

--
Mike Wills
http://mikewills.me