Eliminate the obvious stuff first: are you online when you play ME2? Most games have the select storage option (can't remember if ME2 is one of those though I suspect not) right at the beginning. All you can do is check the options within the game itself.
It might be that because there is no select option that you can't use it directly as you wish to, though you'd probably have figured that out by now after some fiddling about.
Someday someone will find this in a search result and wonder (like the xkcd comic) "WHAT DO YOU FIND OUT, TOROWA, WHAT DID YOU FIND?"
This is for that person.
It appears the only time ME2 asks you for a save location is when you make your very first save on a new career. There is never another option to change save location. (It happily accepts cloud storage as a save option.)
I haven't yet tested whether ME2 will detect a save that has been moved to cloud storage. If so, that essentially solves the issue. Will report back.