To be

According to my understanding
He was to come at 8 pm.(Means He was supposed to come at 8 pm)He had to come at 8 pm.(Means He was obligated to come at 8 pm)

There are two more sentences.

How would she feel if her mother was to be made to stand and wait.(Means her mother was asked to stand and wait by someone)

How would she feel if her mother had to be made to stand and wait.

(Means her mother had to stand and wait till a chair was free)

Correct me if I am wrong. And explain please.