Sorry, I just saw this question from a while ago -
The short answer is that there are no handicapped entrances to the rides.
Almost all lines are mainstreamed, which means everyone waits in the same line, even with a wheelchair or
scooter.
If you have stamina or mobility problems, you should look into renting a wheelchair or
ECV. Disney does not issue passes to skip any portion of the line.
You CAN get a GAC (Guest Assistance Card) which will allow you to go around those portions of lines in a few queues that have stairs if you cannot walk on stairs (not skip the line, just go a different way)