In regards to your question, what exactly do you mean by a "2010 Sprint Cup configuration file?" Are you talking about a driver roster? If this is the case, the 2010 SRD NASCAR Sprint Cup car set that was just released has a driver roster included with it. You simply extract it to the \series\COT\cars directory in your NR2003 installation.
Scott, im not trying to be an ass, but you need to help us to help you....there is no possible way for us to help you with the little (if that) amount of info your giving us...aah crap and uggh isnt much to go on...