Hi. I'm not suggesting this as a long term solution, but I'm currently developing a software application that, among other things, computes Normalized Power. It can import ride data from a Garmin TCX file as well as several other formats. If you would like to send me one or more TCX files, I'd be happy to load them and give you the results. It computes Normalized Power using the formula in the book Training and Racing with a Power Meter -- I match the Normalized Power of PowerAgent. PM me if you're interested.