Ultrasonic sencor HC-SR04 using control surface library

Hi, I'm very new to this and I have close to no knowledge in backend programming languages, but I am very eager to learn !

This is my project : Multiple digital ultrasonic sensors used to modulate filters in Ableton.

I'm using an arduino Mega + mocoLUFA firmware + control surface library

Control Surface Library

From what I understand, only analog sensors can be used using the library's base codes. I tried to look through the code to see where the analog pins were declared, but it's so complete/complex that it looks like black magic to me. Has anyone used digital sensors with this library ? Would there be a way where I could tweak the code to use a digital sensor ? Could I map the digital value to an analog value (in a sense create a DAC ?) ? Am I totally lost and should just buy analog distance sensors ?

Thank you for taking your time in helping me,

Mariska