Reply to Digital button on Analogue circuit w/no +5? (Midi Fighter)

Hey!

I'm expanding the Midi Fighter Classic, and it has room for 4 digi and 4 analogue connections. I have a VERY basic knowledge of electrical connections (I've been watching the tutorials here on DJTT!), and I was wondering if I could connect an additional digital button in place of one of the analogue options, leaving out the power. Would that work as just on/off, or is that a completely different signal that would involve conversion or resistors/capacitors (or something like that)?

The overall idea is this, I added another row of 4 arcade buttons (digital) and I was going to add 3 rotary pots (analogue), leaving me 1 free analogue connection. However, one of the rotary pots is for scrolling through the menu, and it has the option to be pushed down (like to go from crate to folder). The pot has a 3 pin on one side and a 2 pin on the other. So what I wanted to do was hook up the 2 pin from the pot to the ground and A4 (remaining analogue connection) to hopefully use as "crate/folder" and free up one of my arcade buttons.

I'm sure many of you know the answer to this, and I would greatly appreciate the help. Thanks!!