Samson C01U Condenser Mic

I found several sources that mentioned using aggregate devices to get the samson C01U Mic working in Logic Express. The instruction says to choose the C01U and "Built in Audio" from the list in the add aggregate device screen. However, "Built in audio" does not exist whereas "built in output" and "built in input" do. I can get my MIC to work only when I choose built in output along with C01U. The problem is I get output through my speakers when I'm recording. I never did when I used the same mic in Garageband. I am accustomed to hearing the other tracks and not hearing the input stuff I'm recording. This also makes the system prone to feedback. What can I do?