I don't see that NW2.51a or any earlier version of NW2 has tools for reversing and inverting a sequence notes. (Someone please let me know if I'm wrong.) That would be a nice tool to have, and I would think it would be easy to integrate into the program.
There is a NWSW user tool called Retrograde in the starter tools folder of the user tools.
There is another in the .automatic folder of the user tools.