Unfortunately, you can't get the EMR (formerly known as First Responder) certification that quickly.
Usually the courses are offered at a technical college and are an entire semester.
However, if you chose to do it, the EMR course (at least here in WI) is about $300. On the down side, I'd highly recommend just going a head and getting your EMT-B as you get more hands on learning and you learn more skills on top of what the EMR will receive.