Launch Remote Desktop and click on the 'Local Resources' tab.
I have used the Local Resources tab many times to change printer and audio settings. That 'More...' button hides some neat features. Click on 'More...'
After clicking 'More...' you will have a list of all the drives available on your local PC. Check the box next to the drives you want to have mapped to the remote system.
After you have made the Remote Desktop connection to the remote machine this is how the drive appears on the remote system. There is an 'Other' section in the list of drives. Now you can to copy files back and forth to the remote system directly through the Remote Desktop client connection!