I always let my shop do all the geometry chart figuring. Too much stuff to take into consideration, like seat tube angle and bottom bracket height, among other things. But, don't worry! A good shop deals with ordering people bikes all day long, and you're ahead in the game because you already have a bike that fits.
So, your shop should be able to look at you and your Dolce and compare it to any other bike you're thinking about, and tell you not only what size you need, but how the differences in geometry and materials will affect the ride. If you have any doubts about what they're telling you to order, run it by us. Someone here knows everything.
(not me!)
Have fun! Buying a new bike is so exciting! Can't wait to see what you get.
'02 Eddy Merckx Fuga, Selle An Atomica
'85 Eddy Merckx Professional, Selle An Atomica
'10 Soma Double Cross DC, Selle An Atomica
Slacker on wheels.