I'm afraid that if you are playing BETA on Steam, the actual Dragon Commander game will be a new entry in your Steam library, as that is the way it is organized.
There WILL be a preload, but the BETA data will not count towards that.
However, I think that if you simply copy the beta data to the folder where Dragon Commander regular will be installed, Steam may accept that as "data you already have" and will only download what you need. We could test that out, might work.
