Dear Taha,
If one of the the built-in generator torque or torque control options (simple variable-speed controller, simple induction generator, or Thevenin-Equivalent Circuit) is not applicable to your technology, then, yes, you can implement your own torque logic. There are several methods available to do this e.g. as summarized in my Mar 01, 2016 post in the following forum topic: Active drive-train damping in FAST - #2 by Jason.Jonkman. The exact process will depend on which method you select.
Best regards,