No one has answered you yet, so I'll leave this video to you:
https://www.youtube.com/watch?v=0F4xxcCAJVIThis video have an excelent guide to set all the parameters of T-rex, not only for a single card, but to entire rig (multiple cards)
To convert your overclock, it's:
--cclock -200 --mclock 1100 --pl 75
But watch the video because there's good tips to do some adjustments like locking the core clock on nvidias
And pay attention to your temps, the auto settings for fan speed usually are not good enough to mine, I prefer to set a fixed speed.