Many WinRT APIs are available from desktop applications, in addition to Windows Store applications. Windows.Storage.ApplicationData appears to support desktop apps. Look under the "Requirements" section in the documentation:
Minimum supported client: Windows 8 [Windows Store apps, desktop apps]
Someone at Intel posted on how to use WinRT APIs from desktop apps. The post is from September, 2012, and the screenshots appear to be for an older version of the MSDN documentation. Just keep that in mind.
Dave Bennett of Microsoft has a useful blog post which will introduce you to roaming your app data.
I may have misunderstood you, but I think what I mention above is what you want instead of using the Live Connect APIs.