You should start with a model of an existing transistor and change the numeric values to match your needs. There are descriptions in books on SPICE on each of the parameters.
Because the bipolar device is not a standard device from foundry , it is a special device from my own . I 'd like to make the spice model so that it can be simulated in Hspice or Pspice. I heard IC-CAP can do this job. Any one know where to get a copy of this tool ?
If you have IC_cap and solid knowledge of BJT modeling,it's rather easy to get a bipolar model yourself.But you should do some necessary measurement first.In fact you can find detailed method in IC-cap's mannual.