Do you still have your RN license? Do you still want to be a RN? I am not sure what you mean by having an associates degree so you are not qualified to work in an office. Are you thinking you need a BSN to work in an office? I don’t think that is true. Maybe I misunderstood you.
Can you use a computer and a phone? I am not disabled, but I work from home as a telephone case manager for a drug company. The only physical qualifications are to be able to type and use the phone. It is a great job for some one who is an experienced nurse.
I am also confused about the physical requirements to be a coder. If this is something you would like to do, I would see if the college you were looking at could be convinced that they should accept you and find ways for you succeed. I know many people in wheelchairs who have earned college degrees and who work full time. Sounds like the school needs a little education on the Americans with Disabilities Act and how they need to make accommodations for you. Let us know what happens!