You should be able to save the data already on the memory card to a PC. This will give you a copy of what you have stored on the card. When you install the memory card into the Coolpix, you will lose data if you have to reformat the memory card for it to work properly in the new camera. In any case, it may be that the Coolpix will not be able to 'read' the data stored on the memory card , because it might have been stored in a different format than what was used by the other camera.
If you no longer have your old camera, so as to be able to transfer the data from the card (installed in the old camera) to a PC and as you obviously wish to save the data from it then I suggest that you invest in a USB MultiCard Reader, unless your PC already has one installed, (here is a link for some examples http://www.ebay.com/sch/i.html?_from=R40...) that you can connect to your PC and into which you can insert a variety of different memory cards so that you can transfer the contents of the card into your PC.