Not sure that Mr. Guzman's office handles visas to other countries but you can send them an email just to make sure. Click on link that DB gave you.
If you still want to go this route your best bet is to get an immigration lawyer in Canada since they would be well informed on all things related to immigrating to Canada or getting a visitor visa for your girlfriend.
As a side note I have to add that going through a Canadian Immigration lawyer will not speed things up nor can they guarantee you a visitor visa. All application have to go through the process in Haiti just like everyone else with or without a lawyer.
Good luck
Here's a little something for you to read and a list of lawyers
Canada Immigration Lawyers - Find Immigration Lawyers in Canada