This software was previously available as commercial which means that a user has to buy it before the installation package can be obtained. I've looked through the official website for this product and it doesn't appear to be available anymore which could mean that it has been discontinued from development making it impossible to test it or to provide additional information.
If you have the software installed, access it and then create an event in the calendar. When typing, a simple menu with font tools should open, which could also indicate that it supports custom fonts. If that menu doesn't appear anywhere, then Organize Quick & Easy doesn't have support for custom fonts.