In many BI application you have stored a duration as seconds. To display that on the format HH:MM:SS just use the following SQL(Replace 100 with your column name):
SELECT convert(char(8),dateadd(second,100,0),108) as [Duration]
Wich yield the result
As in my previous blogpost where I did the same in analysis services, this only works if the duration is below 24 hours, else you have to do some additional logic.