Please don't start multiple threads on the same topic--or crosspost the same thread in multiple forums. You should explain or show samples of how the number can vary. Is it always at least 5 digits so that we can assume there are always two digits representing minutes and seconds? If so, use a formula like this:
stringvar x := totext({table.number},"000000");
left(x,2)+":"+mid(x,3,2)+":"+right(x,2)
-LB