97 JGC Vacuum Feed To Heating/Cooling System

Having at this again. Dry rotted tube going through a slot in the firewall that feeds vacuum to the in dash system. I can’t see anything through the slot and I have the dash partly taken out to find what the tube connects to. Does anyone have any idea where what I’m looking for is? What it looks like? What it’s called?

Thanks...

Had to take the mechanic plunge on this one. No way to snake a new vacuum hose in or replace a blend door without dropping the climate control box out. Rented a car too, not thinking it’ll be drivable while (if I had to do it) the console and steering column are in the back seat.
Hey, I tried...

Turns out it wasn’t the blend door itself, just a mouse condo in my blend box. While the mechanic was in there, he cleared the condo, replaced the vacuum hose and changed out the heater core. Heat works good again, for a Jeep...