VISAS (Paris)

i am an educated american with two job offers here in paris. only problem is that i do not have a work permit. i understand that a company has to get one for me when they want to hire me, so i don't understand why they then say they CAN'T hire me because of the visa. i know there a a lot of people expatriated here, so how do they do it??? do they really only come from companies of their country of origin? can anyone help me? i want to at least do whatever needs to be done on this side before i am forced to go back home to re-start the process from there.

thanks SO much!