I utilize @rtrouton method of grabbing the installer from the App Store:
http://derflounder.wordpress.com/2013/10/19/downloading-microsofts-remote-desktop-installer-package-from-the-app-store/
Once I have the installer downloaded, I simply drop that into Casper Admin.
@stevewood mentioned the best way to do it. Be aware of some apps needing, or not needing, the _MASReceipt folder under:
/Applications/<AppName>/Contents/_MASReceipt
sometimes just the folder needs to exists or you may need a blank "receipts" file in there. Refer to: https://jamfnation.jamfsoftware.com/discussion.html?id=10327 for some more information on that. I had issues with GarageBand working without this folder, and from what I understand if that folder doesn't exist it may not report as needing an update from the App Store. In some environments you may not to want your end-user updating apps with their own AppleID in the App Store.
Good luck!