Syntax for cast?

this one is failing, its sql server syntax, I want to process only the
previous week's sales.


SELECT `OEINH2`.`IHDOCD`,
`OEINH2`.`IHINV#`,
`ADRES1`.`ADINTA`
FROM
ASTDTA`.`OEINH2` `OEINH2`
INNER JOIN `ASTDTA`.`ADRES1` `ADRES1`
ON `OEINH2`.`IHGRC#` = `ADRES1`.`ADENT#` + `ADRES1`.`ADSFX#`
WHERE
CAST(CONVERT(VARCHAR, `OEINH2`.`IHDOCD`) AS DATE) BETWEEN dateadd(wk,
datediff(wk, 0, getdate()) - 1, 0) -1 AND dateadd(wk, datediff(wk, 0,
getdate()) - 1, 0) + 6
ORDER BY `OEINH2`.`IHINV#`