If remote access is enabled on the computer, you need to modify one of the policies to enable access to the computer's CD drives within a session. To do this, run the editor for local group policies (gpedit.msc). In the console tree, open the following path: Computer Configuration -> Administrative Templates -> System -> Removable Storage Access. Find the All Removable Storage: Allow direct access in remote sessions policy and set it to Enabled.
Once you have modified the policy settings as described here, you should be able to access all CD drives on the computer, and thus all virtual drives, within a session.