Someone on this forum said this can be done in Calibre but I don't have it.
I found that the parasitic R, Cs can be export in Astro, but not the design itself.
Maybe I missed something in Astro or I have to do it with some other tools?
you can extract spf netlist with star-rcxt, which can be read by spice
hercules can do it too
by the way, the RC extract by Astro is not done by itself, it call star-rcxt to do that