I can't give any suggestions without a better idea of what you're trying to do.

Are you trying to do something with $random or $rdist in the Verilog-A model, or do you just want to pass some random values to parameters of your module (so you would just put the appropriate GAUSS calls in the netlist)?

Like I said: your two options are to pass GAUSS as a parameter value, or within the module to use one of the $rdist_ functions to add a variation to the width that's actually used in the current computation.  Be careful, though, that you don't get a different random value for each timepoint if you use the latter approach.