Thanks to recent changes by IFTTT and Microsoft, Push2Run now works with Cortana as well.
Setup is the exact same as described here ( http://www.push2run.com/setup.html ) except in step 11 where rather than creating the IFTTT applet to work with your Google Assistant you set it up to work with Cortana, and in step 12 where you select the option to 'Say a phrase with text'.
Using Push2Run with Cortana gives you finer control over what your computer does when it hears you speak.
The great part of this is that you can set up IFTTT applets for either or both your Google Assistant or Cortana and then use the one that suits you the best.