I just found out that my daughter is not mine after seven years.  A
couple of years ago her mother put me on child support.  I was paying
and then got behind in the payments.  I moved to the US and married. 
The problem is that I had a court case for child support and did not
go.  When my daughter came over to the states this summer, I had a DNA
test done.  I was excluded as the father, 0% probability.  In
contacting a lawyer over in the Bahamas I was told that I will still
have to pay back child support and take another test in the Bahamas. 
Do anyone have any insight into this type of situation?

If that's what you were advised to do (hopefully by a knowlegeable
person) then do it. The case is before a court in the Bahamas and that
is where it will have to be resolved.