If I was guessing, I'd say probably not. There has to be support there for a ladder. If Coachmen didn't offer a ladder as an option, you're probably out of luck.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity
We have a 246rks Coachmen Freedom Express, without a ladder. I purchased an aluminum folding ladder on Amazon for access to the roof, and to make sure the slide has no debris on it before retracting. If the unit did not come with the option for a ladder, one probably cannot be safely attached. As others have suggested, contact the manufacturer to be sure.
My 2015 Coachmen Freedom Express 310BHDS came without a ladder and I wanted to add one. I used Forest Rivers website "contact us" asking for the same info you are wanting. FR sent me a nice printout of the back wall of my TT. There are two (2) wooden 2x4's mounted sideways within the back wall for attaching a ladder. Once I had the print, then did the measurements using blue masking tape to identify the studs, the mounting screws for the ladder went right into the studs.