ELC do not recognizing spectre format model file well

Hi, all

I am doing std cell characterazation using ELC. And I use a model file from TSMC, it defines multiple sections for different processes and corner. At each section, it defines many parameters which has unique values to that process and/or corner, then it include the mos model which uses these parameter to describe its characters. The ELC could direct into the right section and include the mos model well, but it seems it does not recognize the parameter definition. It reports errors when I do "db_spice". Reported errors like:

Error found by spectre during hierarchy flattening. ERROR (SFE-1999): "/home/abc/works/elc/foo.ipdb/NCH.device/simulate/model" 4: Model `nch.1': parameter `wmin': Unknown parameter name `dxw' found in expression.

This model file works well with spectre in virtuoso, but not with ELC.  

Anybody could help me with this? Thanks in advance!

ps. In the elcUG dorcument, under the SPICE Input directory, it said "An optional parameter library file, which defines the device parameters for different process corners" but no more detials following. Anyone know how to write this file and how to include it in ELC project?