I need to get to Brussels, from Charleston, SC (or Atlanta/Charlotte if that is the cheapest way).

I am going there for 4 months, need to be there by a set date, but can be there earlier, and also have to stay until a set date, but can stay longer.

It is Jan 2010 to April 2010, but the exact date, I do not know yet.

What is the cheapest but best way to do this?

Thanks everyone!!