you have Vdd and Iin as voltage and current sources. To define voltage and current sources, you can use the command

System{

Vsource_pset vdd (in1 0) {dc = 1V }

Isource_pset Iin (in2 in1) { dc = 0.1uA }

NTFET ntfet1 ( "source"=0 "drain"=in2 "gate"=in2 )

}

Here NTFET is the device (black box) defined at the top of sdevice like

Device NTFET {.......}