I have not tried this...but I have considered using the 3M Command product to attach a handrail on the camper exterior of the camper. You can look at this link and see that these items do have some strength.
I can't figure out how many pounds of pressure/force a person would use in grabbing a handrail. So I think you would have to do some trail and error research to see if the thing would stick or not. I have had some of these in the TB bathroom near the shower for 2 years. The help hold the clear vinyl in place on the inside of exterior wall during showers
I think it might be possible to attach a hand rail to some sore of round or square material securely and then attach that to the exterior of the TM with Command Strips.
It may pop off and it might not. If you have to grab and pull on it to haul your butt up or inside...it might not work...if it is more to steady to it might be fine.
I did find this chart of the Weight limits of 3M Command products:
http://www.command.com/wps/portal/3M...Weight-Limits/
If I decide to use something like this...I would use the Picture Hanging Strips and unvelcro and store the hand rail before folding the TM.
BTW...The 3M Command products are WONDERFUL! I wish I had invented them!
They all have a little tab ...and when you pull the tab the 3M strip disengages from the wall etc...and leaves no residue/damage.