Hi Srikanth,
The easiest would be create the new node in BW (maybe in ECC if its loaded from there).
alternative would be create a BW hierarchy using self as a data source, there are some document out there to show you how to do that. then it will be a easier load into BPC.
If you want to load during BPC load, then you need to use start and end routine, one thing to remember is that the node name must be in the dimension as a master data before the hierarchy load.
Andy