Post has a few meanings: 1) After. Pre is the opposite and means before. Pre world war 1 and Post world war 1. 2) The mail, or a post office. 3) A newspaper. The Washington Post. 4) A job or role. #4 is what this is referring to. When you are stationed in the military, you are assigned a post. You are assigned or posted to a certain area or to a certain job. Outside of the military this context is also used, though rarely. It would be more common to ask someone what their role is in a company, as opposed to their post. "office assistant" is definitely a job or role. "post" is a job or a role. "Help" is another name for an employee. "Help Wanted" means we're hiring. "Treat the help with respect," refers to the employees or staff. I just have never heard "post help" used together without other words.

My initial thought was the same as Ryan's, but now that I see the context, I believe "post" is the (mainly British) term for "mail." BTW, in the US, the word post is mainly used in the compound word "post office."

It might be in the form of post-() help such as post-operative help. The post is a suffix meaning after sth. hope I am right.

Look at the notes below. You will hear a man asking a colleague for information about r former employee. You have fifteen seconds to read through the note. [pause] Now listen，and fill in the spaces. [pause] Woman： Marketing. Man： Good morning, this is Tom, from Human Resource. Woman： Hi, Tom. Man: I’ve received a letter from the tax office about a former part-timer who worked here last month—I wonder if you could look him up in your records. Woman： Sure，what’s the name? Man： Derek Green. Woman： How does he spell his given name? Man： G-R-E-E-N. Got it? Woman： Oh yes, is he living in No. 52 Rosefield Road, Fox Town? Man： Yes，that’s the one. Woman： He was working in Finance, right? Man: Yes, Customer Service, to be exact. Woman： I can see from the records that they had lots of students working for them last summer. Man: Well, the people from the tax office want to know what his exact job title was —I'm not sure why. Woman： Mm, let me see. He worked as an office assistant. Man： Right, got that. Could you please tell me how much he earned a month? extra listening material got from the exam, does anyone have some more ideas now?

Do you have the sentence it was in, for context?