No it dosent only have frequency. U can definitely use it for
transient simulation.It is called numerator-denominator form.
Following is a usage :

module test(pin, nin, pout, nout);
 electrical pin, nin, pout, nout;
 real nn[0:2];
 real dd[0:2];
 analog begin
 @(initial_step) begin
   nn[0] = 1.0;
   nn[1] = 0.0;
   nn[2] = 0.0;
   dd[0] = 1.0;
   dd[1] = 1.0;
   dd[2] = 1.0;
  end
  V(pout, nout) <+ laplace_nd(V(pin,nin), nn, dd);
 end
endmodule

It is meant to model your filters.

Regards,
Sumit