DC simulation using Spectre Simulink co-simulation

Hello

I have a Verilog-A model (DC) for a transistor and the gate capacitances are modeled in simulink environment. I want to connect and simulate both models using co-simulation. Now, I have noticed that "spectreRF Engine" in simulink can be only connected to AC source while I want to use analyze transistor using DC source in simulink model. for example: [DC source]--->[simulink capcitor_model]--->[SpectreRF Engine]--->Scope[output]

SpectreRF only supports analog inputs? Any hints how I could use DC source in co simulation?

Farhan