The new URL for the Allegro products community site, formerly known as www.specctraquest.com, is www.allegrosi.com. Originally posted in cdnusers.org by Moderator
However, the file you reference was not included in the new technical resources section. This utility was written by contributed by Peter LaFlamme from AMCC. According to Peter, "Cadence SPECCTRAQuest has a spc2spc utility which allows you to extract a spice model of your netlist. It allows you to designate whether you want W-lines , or T-lines. The sigexplorer has a 2D field solver which creates RLGC files for w-lines that you extract. There is also a learning curve associated, but it is also pretty easy to use."
I have attached the file here