Microsoft Word 2010 enables equation editing through the Equation Editor.

It is possible to use shortcuts similar to LaTeX code in order to enter equations in a more fluent manner than clicking on the toolbar for each symbol. One of these shortcuts, for ⟺, is `\longleftrightarrow`

but this symbol is in very frequent use for me and I want to use `\iff`

instead of the current very long "short"-cut. I was unable to find a standard way of modifying this shortcut or adding a new one. How can I go around this issue?