This is the JR trainer cord
http://www.horizonhobby.com/Products...ProdID=JRPA130
not so expensive that you need to worry about Radio Shack or the like.
There are also cheaper ones available that will work
http://www.horizonhobby.com/Search/D...ER+CORD&CatId=
This REALLY should eliminate RS from the picture. Your LHS should be able to get you one or order it yourself. Your instructor may already have one too. I know I keep one with me at all times.