This is an SQL 2000 database my query is:

SELECT EXTENSION, timestamp, CONVERT(VARCHAR,Duration / 60) + ':' + RIGHT('00' + CONVERT(VARCHAR,duration % 60),2) as DURATION

FROM CDR

WHERE (TIMESTAMP BETWEEN CONVERT(DATETIME, '2012-10-01 00:00:00', 102) AND CONVERT(DATETIME, '2012-10-31 23:59:59', 102))

The DURATION field is int datatype and the raw data is 16167. Conversion looks like 269:27 which should be 04:29:07 this is for one call.