Child support question?

i have a 4 month old daughter, and me and her father recently seperated and i am trying to get child support under way. well he also has a 4 year old daughter with another woman, who he pays 800.00 a month in child support the girl does go to daycare so 400 of it goes to daycare and 400 to her. well he told me that the state can only take up to 50% of his wages and his ex already gets like 30-40% so i would only get the remaining like 10%? also she works steadily and has a pretty good income and i am currently unemployed (but im working on getting a job) is all this true will she still get more than me? sense i have to get a job i will have to put my daughter in daycare as well. i thought it would lower her amount and we would just get the same. im comfused?