Looking back at the history of this email it doesn't look like you have spent much time in the documentation. Please take a look at Cadence's documentation, it is very good and there is some very helpful information about creating and placing pcells.
It looks like when you place a pcell, the CDF (this is what controls what appears on the Create Instance form) is only displaying the hspiceModelMenu parameter, but it is not displaying the hspiceModel parameter. From what you sent, you can see this. For the hspiceModel parameter, the display is set to nil and the editable is set to nil. Your form apparently prompts you with Model Name and a cyclic field. The default value for the cyclic field is nshort. When you change this, there is a callback associated with it. The callback is a Skill procedure that will run when this parameter is changed. In your case, the Skill procedure is called CDFmodelFetCallback and it is receiving the arguments of t and "nfet".
You should find where this procedure is defined and take a look at what it does. If you don't know where this procedure is defined, use the following command to show the procedure in your CIW: pp(CDFmodelFetCallback)
One way to figure out what parameters need to be set on your instance using skill code is to see what parameters are set when placing the pcell interactively.
1. Use the Create Instance form to place one of these pcells.
2. Click the Defaults button at the top of the form and place one instance
3. Select that instance in the window and in your CIW, run the following command:
This should show you all parameters that were physically set on that instance. Note the name, type and value. Most likely, a default instance will not have any properties.
4. Place another instance, this time change the Model Name parameter to "nhv".
5. Repeat step 3 and this time you should see that hspiceModel is likely set, as well as hspiceModelMenu and possibly some other values. Whatever you see set at this time, is what you should include in your parameter list when using dbCreateParamInst.