Yes, except that you aren't exempted from the knowledge exam. You're exempted from the driving course that is mandatory for new drivers.
Also, the IDP doesn't replace the Lebanese licence. It's in addition to it. I think for the first six months you can drive with the Lebanese licence only, but if it's in Arabic only, it's recommended to have an IDP as well. Never drive with only the IDP, as it's not valid on its own.
Here is a description of the process one Lebanese immigrant went through. If you've never held a Quebec licence, and resided in Lebanon when you obtained the Lebanese one, then you'll be in the same situation even though you're a Canadian citizen. Be prepared to provide proof of residence in Lebanon.
http://www.forum.immigrer.com/topic/111449-permis-de-conduire-vos-experiences-et-conseils/