I hope it helps. I will show you how to use it. For alphanumeric characters and symbols available on keyboard you can type it out.
In this article you are going to study the first optionEquation and the next article you will go to learn about symbols.
Simply click Translate to LaTeX or use shortkey AltEnter. If you know the name of a symbol simply type followed by the symbol name. After you insert the equation the Equation Tools Design tab opens with symbols and structures that can be added to your equation. Fortunately MathType has Tex translator.