How to handle complex numbers and error function (erf(x)) in VerilogA

As far as I know, verilogA does not support equation containing complex 
numbers and it doesnt work with the error function. I have just started 
a project simulating a specific FinFet for a company and I need to use 
equations based on the requiremets mentionated.  Is there any way? or 
any clue that I could use in order to star my investigation.

Thanks.