Work / University requirments in Poland. I already have a diploma from Ireland. [6]

Hi there,

I want to study in Warsaw. I have lived here for one year.I already have a diploma from my university in Ireland but i would like to study business with polish in warsaw. What university is the best as most of the universities ive looked at focus on international relations and political science or english lit. And also are high school results very important in deciding if you get accepted or not or would my previous university results be sufficient?

Please reply with helpful information as usually when i post something people reply and go off the topic and start a new conversation. This is very important to me. Thanks. :-)