Will Asterisk do this? (yet another newbie question)

I have been browsing the forums to find an answer to my questions, but haven’t come up with one so here I go, and please forgive me if it has been asked before:

A friend of mine needs to answer calls from 3 external companies, and be able to see which company the diverted call came from (She has to answer with the company name etc.).

What would be the simplest, cheapest (especially on the side of the 3 companies) implementation?

Thanks in advance.