Importing in LR3

LRussoPhoto

What I am trying to do is copy 2 sub folders(by holding down control and clicking on each to high light them) from a folder on my external drive and putting them on my new portable drive. When I try to do it, it only copies the pictures into the main folder and doesnt bring them over within each sub folder(it does the same thing when I try to do it with one folder too). Resulting in me having to then create a new sub folder on the portable drive after the photos have been moved. I could also create that new sub folder on the portable before the copy but I want to know if I can copy the whole sub folder instead of creating new ons.