Problem with RAW and 3rd party software is that the software company has to reverse-engineer it to get it to work. The D70 files can be read by Photoshop CS, but you might need to download the (free) update for it. The other option is to use Nikon Capture to convert the RAW image, save as a TIFF (or jpeg) and then bring into Photoshop.

If you have to buy Nikon Capture, you might be better off just upgrading to Photoshop CS, it should save you a lot of time. I don't have Capture (using a Fuji DSLR) and I know it does some things CS doesn't do, but for most situations CS will probably be the quickest way to get the job done.