You can use Wave as if it were another microphone, even with the Wave Link software completely closed.
Just set the Elgato microphone as your input device in Voicemod and Windows.
And for the output device, you can set the usual Windows output (Speakers: Realtek High Definition Audio) or the Wave output (Headphone (2-Elgato Wave:3)) depending on what you want to use.
But if you want to use Elgato's software, Wave Link, to handle all your audio, including Voicemod, you must set it up this way:
Once everything is set up, all you have to do is add the Voicemod microphone: