Use Copy Manager to backup wd_backup folder or sparsebundle file

Hi

I would like to make a backup of the sparsebundle file created by TimeMachine on the MBWE. 

I have a usb drive plugged into the back of the MBWE. Copy Manager can not see the wd_backup folder that the sparsebundle is located in.

How can I do this without mapping the folder in Finder and dragging the file across etc?

Any help will be greatly appreciated.

Thanks

D

The usb port in the back of the my book is only used for extra storage you will not be able to see the drive as another letter