Hi! Right now, the only way I know to do that is if you're using the xRC to ADVance MS integration. If you do, then you can choose the net mode per block. For example, you could choose RCC for one block and R for another and C for another. Without using the XRC to ADVance MS integration, there's no way to do this. The only thing you can do is extract lumped C for everything, then RCC for select nets. But then you'd have to name each select net that you want RCC for.
Thanks! 'PEX NETLIST ADMS' is exactly what I was looking for!
Have you had a chance to try it out yet?