Como converter 3/4 de caracteres inteiros para o formato de 24 horas e combinar com a data?

;WITH CTE AS
(
    SELECT  *,
            DATEADD(HOUR,DOCTIME/100,DOCDATE) DocDateHour,
            CAST(RIGHT(DOCTIME,2) AS INT) DocTimeOnly
    FROM OPOR
)
SELECT DATEADD(MINUTE,DocTimeOnly,DocDateHour)
FROM CTE