Mariange,
You can obtain some more information about Chartered Secretaries from this website:
www.icsa.org There is a "what is a Chartered Secretary?" section, which you will find very helpful. As you will see, a chartered secretary is usually quite a high-ranking individual in an organisation. The qualification you can obtain in England is internationally recognised.
Some Chartered Secretaries are Company Secretaries, whilst others work at CEO level or perhaps in a legal/advisory capacity. It's a very flexible qualification which can be a stepping stone to lots of opportunities.
I've just completed my law exams and am considering taking this extra step (in my bid for world domination, as my husband says). It's jolly hard work, but I think it is worth it if you want to progress up the career ladder. So, I wish you success if you decide to embark on this course of instruction.