I've never heard of Rogers. But I can tell you one thing, on the internet you can find codes to unlock your sidekick slide. If you can't find anything for free, for a small amount of money you can get the code and instructions from someone. And if it's unlocked and Rogers uses a SIM card, then it will work.
So yes, you can unlock it & use the Sidekick Slide with Rogers.
And, I'm not sure how difficult this is going to be, but best of luck!