Start from the inside and work your way out:

DECLARE

@minutes int = 17562

,@minportion int

,@hours int

,@hourportion int

,@days int

,@ddhhmm char(8)

SET @minportion = @minutes%60

SET @hours = (@minutes - @minportion)/60

SET @hourportion = @hours%24

SET @days = (@hours - @hourportion)/24

SET @ddhhmm = CAST(@days AS char(2))+':'+CAST(@hourportion AS char(2))+':'+CAST(@minportion AS char(2))

SELECT @ddhhmm

Put it all together:

SELECT CAST(((@minutes - ((@minutes - @minutes%60)/60)%24)/60 - ((@minutes - @minutes%60)/60)%24)/24 AS char(2))+':'+CAST(((@minutes - @minutes%60)/60)%24 AS char(2))+':'+CAST(@minutes%60 AS char(2))

You'd want to make it a little bit more sophisticated than I've done, perhaps by padding with leading zeros, or by allowing for numbers of days greater than 99.

John