By layout, I was referring not to the physical keyboard, but to the input language specified in the operating system settings. On Windows: If you've set it to US English, then pushing the key to the left of the '1' key should produce a backtick. If you've set it to French, then which key or combination you need to push will depend on exactly which layout you've selected. If it's the one titled "Canadian French", then pushing the key to the left of the Enter key should produce a backtick, though you may need to push it twice, or push spacebar afterwards, because it's a "dead key", which is supposed to be used in sequence with another key to produce an accented character. If you're using "Canadian Multilingual Standard", however, you'll need to push Alt Gr + the key to the right of the letter 'P', again with the same "dead key" qualifications. Since you say pushing the key to the left of the Enter key produces "è", you're probably using "Canadian Multilingual Standard". The relevant settings are in the control panel, under region & language.
But it all varies depending on OS and version, and requires looking up exactly what you're using. On a Mac, the settings are probably under System Preferences » Language & Text » Input Sources, where you can examine different keyboard layouts to find particular keys. As for Linux... Even specifying that it's Mint doesn't narrow it down sufficiently, due to the level of customization possible with Linux. The location of the relevant settings is going to depend on which desktop environment you're using, or it might even just be buried in some config file somewhere in /etc.