This has always been an odd argument for god. Basically it states that with out a moral law giver, there can be no objective morals. There are objective morals. Therefore there's a god.
Flaws with this argument:
1: The main flaw with this argument is that there does not have to be objective morals.
2: The moral law giver does not have to be a god. Evolution and/or society can function as the moral law giver. The drastic shifts in morality over time and in different societies indicates that this is the case.
3: This would not get you past deism. There is no way of knowing which, if any, of the roughly 150,000 known religions had it right.